Say birkat ha'mazon instead of al ha'michya if you ate enough bread-like foods (mezonot) or bread-like food combinations (such as crackers with tuna salad) to be the volume of your normal biggest meal of the day. This is true even if:

• You had not planned to have a meal (for example, you planned to eat only one slice of pizza but then ate two more), and
• Did not wash your hands before the meal.

 

Don't fold clothes (including a talit) on an existing crease on Shabbat.

Note Taking three steps backward immediately before taking three steps forward, as instructed in some siddurs, defeats the purpose of taking the three steps forward. The purpose of stepping forward is to symbolically approach Hashem. If you step backward and then take your three steps forward, you are back to where you began and have not approached Hashem at all! 
If you do not have enough room in front of yourself to take three steps forward when beginning your amida, step back somewhat (at least a few seconds) before you say ga'al Yisrael. There is no need to take three steps back; a single large step that will give you room to take three steps forward is all that is needed.
By making a practice of taking three steps back, people have made the stepping backward part of the entire procedure, and it should not be.

Similarly, once you have finished saying the amida and walked three steps backward, wait at least three seconds before walking forward so as not to defeat the purpose of having stepped backward. Take as many steps as you need to get back to your seat--one step should suffice. 

You may not wash or hang up wet laundry on Jewish festivals (or Shabbat).  The halachot for drying laundry depend on whether you use a clothesline or a dryer:
Jewish Festivals: Laundry: Clothesline
You may only take down laundry on Jewish festivals if it was dry before sunset at the start of the festival, and only if you don't:

• Transfer the laundry from one halachic domain to another (hotza'a), or
• Give the impression that the laundry had been washed on the Jewish festival (mar'it ayin).

If laundry on a clothesline is still wet at sunset before the festival, the laundry is muktza and you may not take it down or use it during the festival. This is different from the case of a dryer.
Reason On the clothes line, there is no certainty that the laundry will dry during the festival (it might rain, it might be cold or cloudy...), so the person may not have in mind that it will dry during the festival.
Jewish Festivals: Laundry: Dryer
Laundry in a dryer (even if it was wet at sunset) that was turned on before sunset beginning the Jewish festival (or Shabbat) is not muktza, even if you do not intend to wear it.  You may remove the dry laundry from the dryer on the Jewish festival as long as no light goes on.

On Jewish festivals, you may not separate challa from loaves baked before the festival, as follows:

• In Eretz Yisrael, you may not eat bread from which challa was not separated if required (for more details, see Separating the Challa Portion and Challa Separation) until after the Jewish festival ends and you have separated the challa.
• Outside Eretz Yisrael, you may:
  • Leave one loaf until after the Jewish festival,
  • Eat as much as you want of the remaining loaves, and then
  • Separate the challa from the loaf after havdala.

You may dispose of a lulav in any way that is not degrading. So, you may drop it into a field or put it on a lawn--unless animals might eat it or step on it or if it will be subject to poor treatment before it decays.  Don't dispose of a lulav or etrog directly into the garbage. Burn, bury, or wrap them in a bag or one layer of plastic and you may throw it into normal garbage.

Say ha'tov v'ha'meitiv instead of she'hecheyanu when two or more people benefit from or enjoy something. 

You may ride in a vehicle with a non-Jewish driver on Shabbat only if:

• He or she doesn't do anything especially for you (for instance, the non-Jew is driving somewhere anyway and offers you a ride for free), and
• There is no possibility of mar'it ayin (appearing to do something not allowed, even though the act is technically allowed). 

However:

• You must not open a door (which will turn on a light) or do any other melacha while riding with a non-Jewish driver on Shabbat.
• You may continue to ride on a bus or other public vehicle driven by a non-Jew even once the sun sets on Friday if you have already paid (or if it is free) and if the vehicle is not being driven just for you.
• You may not continue to ride in a car or taxi that is being driven for you once the sun sets on Friday even if you have already paid for it or if it is free, unless it will be dangerous for you to get out of the vehicle and walk to a safe place.
• You may not invite for a Shabbat meal Jews who may drive themselves to your home on Shabbat unless there is more than a 50\% chance that they will arrive without driving on Shabbat.

B'di'avad, you may scoop out mayonnaise or mustard and spread it on meat and then scoop out more and then later use same condiment on dairy foods (and the same for dairy and later on meat) as long as any residual food is less than 1/60th of the total volume of food. But the preferred practice is to have two separate containers, one for dairy and one for meat foods.
 

You may ride on an elevator if:

• The elevator stops at all floors, or
• A non-Jew pushes the button in order to ride the elevator himself.

If you recite birkat ha'mazon after se'uda shlishit over a cup of wine, you may only drink the wine if the meal ended before sunset.  

Jewish Festivals are listed in the Torah and are of two types: 

1. Three pilgrimage festivals (shalosh regalim):

• Passover,
• Shavuot, and
• Sukkot (including Shimini Atzeret).

These festivals were celebrated in ancient times by "appearing before God"--by bringing offerings to the Tabernacle or Temple.

2. High Holidays: 

• The Jewish New Year (Rosh Hashana—“Yom Teru'a” in the Torah), and the
• Day of Atonement (Yom Kippur).

 
Duration
Jewish holidays that were originally one day are now observed as follows:

• Rosh Hashana--2 days.
• Yom Kippur--1 day.
• Shavuot--1 day in Eretz Yisrael or 2 days elsewhere.
• Passover has festival days at the beginning and end of the holiday and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Passover lasts for 7 days in total and the first and last days are festival days. Outside of Eretz Yisrael, Passover lasts 8 days and has two festival days at the beginning and two at the end.
• Sukkot has festival days at the beginning and at the end and intermediary days of lesser holiness, which are called chol ha'moed. In Eretz Yisrael, Sukkot lasts for 8 days and the first and last days are festival days (the last day is Shimini Atzeret). Outside of Eretz Yisrael, Sukkot lasts for 9 days and the first two days and last days are festival days (the 8th day is Shimini Atzeret and the 9th day is Simchat Torah).

Character
Each holiday contributes its own character to Jewish life (Passover--the theme of freedom; Yom Kippur brings atonement, etc.). 

Celebrating
How to celebrate these holidays is detailed in our Oral Law and halacha books. Jewish festivals as practiced today are similar in holiness to Shabbat. As with Shabbat, the Jewish festival has candle lighting, kiddush at two meals, and havdala.   We eat our best food and wear our best clothing on Jewish festivals (we eat our next-best food and wear our next-best clothing on Shabbat!).
The main idea behind eating meals on Jewish festivals is joy (simcha), so you should drink wine and eat meat (only if you enjoy wine and meat).  There is no third meal on Jewish festivals since people used to eat two meals each day (adding a third meal on Shabbat was for enjoyment/oneg).
 
Melachot
Any activities or actions permitted on Shabbat are also permitted on the Jewish festivals. Actions that are forbidden on Shabbat are generally also forbidden on Jewish festivals, but there are some leniencies (only if the actions are needed for that festival day).
Examples

• Lighting from an existing flame,
• Cooking and baking for the Jewish festival day, and
• Carrying outside the eruv (hotza'a--transferring objects between domains).

 
Grama
Grama (indirectly causing an action) is permitted on Jewish festivals (but not on Shabbat). For example, you may advance or delay a timer that will make a light go on or off in the future (the timer must already be plugged in and operating from before sunset of the festival day).
Note For an action to be considered indirect based on time, there must be at least 2.5 seconds after the first action is done before the resulting action begins to happen.

Psik Reisha Dla Neicha Lei
Psik reisha dla neicha lei is forbidden on Jewish festivals, just as it is on Shabbat.

D'oraita Restrictions
D'oraita restrictions apply world-wide to:

• First and seventh days of Passover,
• First and eighth days of Sukkot,
• First day of Shavuot,
• Yom Kippur,
• First day of Rosh Hashana.

Note The same restrictions apply to all other Jewish festival days but are rabbinical.
 
Women
In general, women are not required to perform the positive, time-dependent commandments. Women and girls are not required to eat any Jewish festival meals except the Passover seder meal (but they are not allowed to fast on those days).

Here are some suggestions (they are NOT halachot!) of what to prepare in advance of Jewish festivals. Add or delete to suit your needs!
  
Candle Lighting

• Check candle lighting time
• Set the candles in their holders (and have matches nearby)

 
Set the Table
Set the table, including the challa and its cover
 
Kitchen Preparation

• Sharpen knives
• Tear paper towels
• Refrigerator: Turn off or unscrew lights; disconnect any LEDs or fans
• Turn on blech, stove, oven, etc., for whatever you will need
• Set up hot water urn
• Turn off stove, oven, if needed

 
Food Preparation

• Thaw frozen meat, fish, and other food that might take hours to defrost before being cooked
• Cook whatever can be cooked ahead of time
• Squeeze lemons; do any other boreir-type preparations
• Chill wine
• Open bottles and cans that will be needed on the Jewish festival

 
Cleaning

• Make beds
• Sweep or vacuum
• Dump garbage

 
Clothing

• Do laundry
• Empty pockets of muktza
• For men, set out Jewish festival talit

 
Muktza
Check that nothing you will need is beneath a muktza item
 
Personal Care

• Cut hair and nails, if needed
• For men, shave or trim beard and mustache, if needed
• Tear dental floss
• Tear toilet paper or put out tissues in bathrooms
• Open any new boxes of tissues

 
Electronics

• Set heat or air conditioning
• Turn on or off lights, or set timers for them
• If desired, turn off or disconnect:

• Alarms 
• Cellphones and phones
• Computers
• Microwave detectors
• Other electronics

Jewish Festivals: Medicines: When To Take
Medicine generally may not be used on the d'oraita Jewish festival days.

Jewish Festivals: Medicine for Chronic Diseases
You may take medicine on Jewish festivals (whether d'oraita or d'rabanan) for:

• Chronic diseases, such as Parkinson's disease, or
• Any disease that affects your entire body.

Jewish Festivals: Medicine for Non-Chronic Diseases
You may take medicine on Jewish festivals for non-chronic illnesses, if skipping one day will prevent cure.  You may not take medicine for non-chronic illnesses if skipping a day will just delay your being cured (unless the disease affects your entire body--in which case, you may take the medicine).

Jewish Festivals: Medicines: When To Take: D'Oraita Festival Days
Here are the d'oraita Jewish festivals:

• First day of Sukkot, Passover, and Shavuot
• Seventh day of Passover
• Shmini Atzeret (8^th day of Sukkot)
• Yom Kippur
• Both days of Rosh Hashana (even though the second day is d'rabanan).

On these days, as well as on d'rabanan Jewish festivals, you:

• MUST take medicine whenever there is any question of a life-threatening disease or condition.
• MAY take medicine for a condition that affects the entire body (illness, weakness, etc.). Consult a rabbi if possible.
  ExceptionYou may not smear substances on skin UNLESS the illness is life-threatening, in which case even smearing is permitted.
• MAY use some medicines if only part of your body is affected by a non-life-threatening disease--consult a rabbi.

Jewish Festivals: Medicines: When To Take: D'Rabanan Festival Days
You make take medicines for any reason on d'rabanan Jewish festivals--even medicines not allowed on the first day of Jewish festivals--except:

• Medicines that you smear on skin.
• If the Jewish festival falls on Shabbat (which can only be second day of Shavuot).

Here are requirements for a hot spring as a mikva:

1. The temperature may not be above 98° F.
2. If the spring and immersing area are separate, any pipes used to bring water into the immersing area from the spring must be at least 3" in diameter. Consult a rabbi.
3. The mikva area must contain at least 40 seah of the spring water.
4. The mikva area must be hewn of rock or poured concrete, etc., but may not be prefabricated in one piece, like a hot tub.
5. The water may not reach the mikva area via a pump.