1 – Reciting the takbeer!
This is one of the greatest Sunnahs on the day of Eid because Allaah says (interpretation of the meaning):
“(He wants that you) must complete the same number (of days), and that you must magnify Allaah [i.e. to say Takbeer (Allaahu Akbar: Allaah is the Most Great)] for having guided you so that you may be grateful to Him” [al-Baqarah 2:185]
In the case of Eid al-Adha, the takbeer begins on the first day of Dhu’l-Hijjah and lasts until sunset on the last of the days of tashreeq.
The format of the takbeer is as follows:
Allaahu akbar, Allaahu akbar, laa ilaaha ill-Allaah, Allaahu akbar, Allaahu akbar, wa Lillaahi’l-hamd (Allaah is Most Great, Allaah is Most Great, there is no god except Allaah, Allaah is Most Great, Allaah is Most Great, and all praise be to Allaah).
Men should raise their voices reciting this dhikr in the marketplaces, mosques and homes, but women should not raise their voices.
2 – Performing ghusl before going out to the prayer
It was narrated in a saheeh hadeeth in al-Muwatta’ and elsewhere that ‘Abd-Allaah ibn ‘Umar used to do ghusl on the day of al-Fitr before going out to the prayer-place in the morning. Al-Muwatta’ 428.
Al- Nawawi (may Allaah have mercy on him) said that the Muslims were unanimously agreed that it is mustahabb to do ghusl for Eid prayer.
The reason why it is mustahabb is the same reason as that for doing ghusl before Jumu’ah and other public gatherings. Rather on Eid the reason is even stronger.3 – You should wear your best clothes
With regard to women, they should not wear beautiful clothes when they go out to the Eid prayer-place, because the Prophet (peace and blessings of Allaah be upon him) said: “Let them go out looking decent” i.e., in regular clothes that are not fancy. It is haraam for them to go out wearing perfume and makeup.4 – Greeting & Congratulations one another
The etiquette of Eid also includes the congratulations and good wishes exchanged by people, no matter what the wording, such as saying to one another Taqabbala Allaah minna wa minkum (May Allaah accept (good deeds) from us and from you” or “Eid mubaarak” and other permissible expressions of congratulations.
It was narrated that Jubayr ibn Nufayr said: When the companions of the Prophet (peace and blessings of Allaah be upon him) met one another on the day of Eid, they would say to one another, “May Allaah accept (good deeds) from us and from you.” Ibn Hajar said, its isnaad is hasan. Al-Fath, 2/446.
5 – It is prescribed for the one who goes out to the Eid prayer to go by one route and return by another
Following the example of the Messenger of Allaah (peace and blessings of Allaah be upon him). This Sunnah does not apply to other prayers, Jumu’ah or anything else, it only applies to Eid.
6 – Eating after the prayer on Eid al-Adha
On Eid al-Adha it is mustahabb not to eat anything until one comes back from the prayer, so he should eat from the udhiyah if he has offered a sacrifice. If he is not going to offer a sacrifice there is nothing wrong with eating before the prayer.