Say shemoneh esrei (amida) with a minyan—ideally starting together. The key is to begin with the other people, even if you will not finish at the same time. You should not begin before the congregation begins saying any amida.

When saying any amida, concentrate (at least for the first blessing) on the idea that you are standing in front of God (but if you did not concentrate, don't repeat the blessing or the amida).
 

If you need to use the toilet, you may not say the amida.

On Shabbat, even if there will not be at least nine men answering amen to the reader's repetition of the amida, the reader should say the repetition anyway, without intending that his repetition be counted as a nedava (which can only be offered on weekdays). If less than six men will be answering, the leader must wait before doing the repetition.
 

See Attire for Amida.

If you forgot to say, or incorrectly said, a phrase in the amida, you must correct your errors in:

• Mashiv ha'ruach
• Ha'el ha'kadosh
• Tein bracha/Tein tal u'matar l'vracha
• Ya'ale v'yavo (except Rosh Chodesh night).

Do not correct errors in other additions/changes if you have already said the blessing for that paragraph, such as:

• Rosh Hashana, Yom Kippur, and Ten Days of Repentance changes (except ha'melech ha'kadosh)
• Al ha'nisim
• Aneinu
• Ya'ale v'yavo (if Rosh Chodesh night).

If you arrive late for any minyan (except ma'ariv) that is about to start the amida, try to finish saying your amida before the leader gets to kedusha, if you can.
If you know you will not be able to finish your amida in time to say kedusha with the minyan:

• Wait for the leader to start the repetition of the amida.
• Say the repetition of the amida word for word with the leader, including kedusha, until the end of the third blessing (ha'el ha'kadosh).
• Once you and he have both finished saying the third blessing, you may continue at your own pace regardless of whether you will finish before or after him.

If for any reason you have not yet finished saying your amida by the time the leader begins saying the reader's repetition, do not say amen or any other replies to the prayer leader's repetition. However, when he begins to say kedusha or kaddish:

• Pause in your own amida and listen without answering or saying anything.
• Once the leader has finished kedusha (that is, he has said baruch kevod adonai mi'mkomo) or kaddish (that is, he has said da'amiran be'alma v'imru amen), resume your private amida.

If you forget a change or addition to the amida during the 10 Days of Repentance (between Rosh Hashana and Yom Kippur), the only one for which you must return or repeat the amida is ha'melech ha'kadosh (third blessing).

Saying the seasonal addition to the amida of mashiv ha'ruach… begins at musaf of Shmini Atzeret. The last time it is said is on the first day of Passover in musaf.

Introduction to Missed Amida/Tashlumim
If you accidentally miss any amida, you may make up for it (tashlumin)--unless you intentionally missed it.

Amida: Errors: Missed Amida/Tashlumin: Regular Days
Missed Ma'ariv Amida
If you accidentally did not say the amida for ma'ariv:

• Say the normal shacharit amida the next morning with the other men in the minyan.
• Say ashrei.
• When the leader begins his repetition of the amida, say the amida along with him, word for word, including kedusha.
• After saying ha'el ha'kadosh, finish your amida at your own pace.
• If you are not with a minyan, say ashrei and then repeat the shacharit amida.

Missed Shacharit Amida
If you accidentally did not say the amida for shacharit:

• Say the normal mincha amida with the other men in the minyan.
• Say ashrei.

• When the leader begins his repetition of the amida, say the amida along with him, word for word, including kedusha.
• After saying ha'el ha'kadosh, finish your amida at your own pace.
• If you are not with a minyan, say ashrei and then say the mincha amida a second time.

Missed Mincha Amida
If you accidentally did not say the amida for mincha:

• Say the normal ma'ariv amida with the other men in the minyan.
• Say ashrei.
• Say the ma'ariv amida a second time. Skip modim.
• If you are not with a minyan, say ashrei a second time and repeat the ma'ariv amida.

Note At the next prayer service, say whatever is the correct amida for that later prayer service, even if it is not the same amida that you missed.
If you miss mincha on Friday, say the ma'ariv service for Shabbat and repeat that amida again.
Note Once the time for the next amida has passed, you may not make up the missed amida.
Example
If you missed mincha on Thursday, you may only say tashlumin for mincha as long as you may still say ma'ariv, which is daybreak of Friday morning.

Amida: Errors: Missed Amida/Tashlumin: Shabbat/Jewish Festivals
Even if you forgot to say a prayer service on Shabbat and Jewish festivals, say the next prayer service amida and repeat THAT amida to make up (tashlumin) for the one you missed--even if it is no longer Shabbat or the Jewish festival.
Exception
There is no tashlumin for musaf. However, you may say musaf until sunset, even if you already said mincha.
Note If the time for mincha has arrived (½ hour after halachic midday), you must say mincha before saying musaf (but if you could join a mincha minyan later, you may say musaf now).
Situation
You miss Shabbat mincha.
What to Do
Say ata chonantanu in ma'ariv, but only for the first time you say the amida, not the second time (which is tashlumin).
Situation
You forget to say ma'ariv on Saturday night.
What to Do
Say ata chonantanu on Sunday morning in the second amida (which is tashlumin).

If Doubt about Whether You Said Amida
If you are not certain whether you said an amida:

• On a weekday, assume that you did not say the amida and say it anyway.  Intend that:
  • If you forgot the previous amida, this makes up for it, and
  • If you did say the previous amida, the second one is a nedava (free-will “offering”).
• On Shabbat and Jewish festivals, do not say the amida twice as tashlumin.

            Reason You may not say a voluntary prayer service (nedava) on these days.
Men who intentionally delayed saying shacharit past the fourth halachic hour of the day still say that amida until midday but if they did not say it by midday, they may not say tashlumin. See Minyan: Keeping Pace: Shacharit Minyan.

When saying the amida yourself, do not say amen or any other replies to the prayer leader's repetition. If he says kedusha or kaddish:

• Pause in your own amida and listen without answering or saying anything.
• Once the leader has finished kedusha or kaddish, resume your private amida.

The minimum attire required for men and women to say the amida is to be dressed appropriately to meet an important and respectable person.

A talit is required only when saying the amida prayer, but the universal custom (for men who wear talitot!) is to wear the talit during the entire shacharit service.
Note A talit is worn for shacharit, musaf, and all day and night on Yom Kippur; it is not commonly worn for mincha or ma'ariv (except on Yom Kippur).

You may bend down during the amida to slide up your socks, scratch your legs through your pants, and other permitted actions.

See What To Pray: Set Prayers: Amida.