We are required to eat two meals on Jewish festivals, each preceded by kiddush, one in the evening and one in the morning. For both meals for each Jewish festival day (and all three meals on Shabbat), say ha'motzi over two complete loaves of bread, each of which is at least 1.3 fl. oz. in volume. 

Source of Saying Jewish Festival Kiddush
Some kiddushes are commanded by the Torah (d'oraita); the others are from Chazal (d'rabanan), as follows:
Kiddush d'Oraita

• First night of Jewish festivals
• Night of seventh day of Passover
• Night of Shmini Atzeret.

Kiddush d'Rabanan

• First day of Jewish festival
• Second night of Jewish festival
• Second day of Jewish festival
• Seventh day of Passover
• Eighth night of Passover
• Eighth day of Passover
• Shmini Atzeret day
• Night and day of Simchat Torah.

Source of Jewish Festival Kiddush Location
Saying Jewish festival kiddush at the place where you will eat your meal is a rabbinical (d'rabanan) enactment.
Jewish Festival Kiddush-Meal Quantities: Evening

• For evening kiddush for a first-night (d'oraita) Jewish festival, a minimum of 4 fl. oz. (119 ml) of wine must be blessed on and at least half must be drunk.
• For evening kiddush for a second-night (d'rabanan) Jewish festival, a minimum of 3.3 fl. oz. (99 ml) of wine must be blessed on and at least 2.0 fl. oz. must be drunk.
• For the evening meal, as on the first two Shabbat meals and for all required Jewish festival meals, a minimum of 1.9 fl. oz. (56 ml) of bread must be eaten within four minutes.

Eating Requirements for Jewish Festival Morning Kiddush
There are two separate eating requirements during the daytime. They may be combined (say/hear kiddush and start the main meal right away) but are often done separately (say/hear kiddush and then eat some light foods and beverages; the main meal is eaten later in the day).
Note Since eating and drinking requirements on all morning kiddushes (both Shabbat and Jewish festivals) are d'rabanan, the required beverage amount for morning kiddush is only 3.3 fl. oz. (99 ml) instead of the d'oraita 4 fl. oz. (119 ml) (which is required for kiddushes for Shabbat evening and all first-night Jewish festivals).

• Morning kiddush requires a halachically legal “meal” with these elements:
  • Blessing on a minimum of 3.3 fl. oz. (99 ml) of wine (or other beverage),
  • Someone's drinking at least half the beverage, followed by
  • Eating at least 1.3 fl. oz. (39 ml, or 1/6 cup) of some type of mezonot within four minutes. 
    Note If you drink at least 3.3 fl. oz. (99 ml) of wine within 30 seconds, you do not need to eat mezonot.
    Note You do not need to drink the wine or other kiddush beverage to fulfill “establishing a meal.” You may hear kiddush and then simply eat the required amount of bread or mezonot. This applies to Shabbat or Jewish festivals, evening or morning.
     

 

• The real meal (kovei'a se'uda) requires eating at least 1.9 fl. oz. (56 ml) of bread (or matza during Passover!) within four minutes. It must include enough food to satiate. 
  Note You can simultaneously fulfill the requirement to “establish a meal” and to “eat a meal” by eating one (the same) piece of bread.

For women's obligation to say or hear Jewish festival morning kiddush, see Jewish Festivals: Kiddush: Who May Make.
 

Women and girls may not apply any nail polish or makeup on Shabbat (and Jewish festivals), including mascara and lipstick. You may not even apply lip coatings such as ChapStick, even if just to prevent chapping.
Note Beware of “Shabbat makeup” that stays on longer than normal makeup but may not be applied on Shabbat.

On Saturday morning, cut the upper challa of the two challot.  (For Jewish festivals, cut the upper loaf at night and day.)

You may not have your hair cut and you may not shave on Jewish festivals (and Shabbat).
 

You may not have your hair cut and you may not shave on Shabbat (and Jewish festivals).
 

It is a custom to make round challa for Rosh Hashana and other Jewish festivals (except Passover!), unless Rosh Hashana falls on Shabbat.

You may add personal requests to the amida on weekdays (not Shabbat or Jewish festivals) in these prayers:

• For livelihood:
  • In the amida's 9^th paragraph (bareich aleinu), between mi'tuvecha and u'vareich shnateinu.
• For a general request:
  • In the amida's 16^th paragraph (shema koleinu), before ki ata shomei'a.
  • Even better, just before saying yihiyu l'ratzon.

 

A business whose sole or major owner is Jewish may not be operated on Shabbat (and Jewish festivals), even by non-Jewish employees.

It is an enhancement of our prayers to give charity at shacharit and mincha (except on Shabbat and Jewish festivals).

You may not end Shabbat before dark (appearance of three medium-size stars--tzeit ha'kochavim).
When Is Dark
Shabbat (and Jewish festivals) ends at “dark”: when three medium-sized stars are visible overhead.
If you are in a place where the sun sets but the sky will not get dark any time that evening, ask a rabbi what to do.

At the Passover seder, all Jews above the age of bar mitzva or bat mitzva (including women--unlike on other Jewish festivals) must drink wine for kiddush and for the other three times in the seder when the borei pri ha'gafen blessing is said.

You may change weights on barbells or on a completely mechanical (no electrical parts; no timers or indicators) weight machine on Jewish festivals but only for enjoyment, not for exercise.

When kashering an oven or utensils for Passover, you may kasher:

• By Libun

• By Hag'ala