Some sunnah of Eid al Adha:
-Eating after the prayer:
It is mustahabb not to eat anything until one comes back from the prayer (so one should eat from the sacrifice if he has offered it. If he is not going to offer a sacrifice there is nothing wrong with eating before the prayer).
-Doing ablution (ghusl) before going out to the prayer.
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) .
-Takbeer on the day of Eid
Ibn Shihaab al-Zuhri (may Allaah have mercy on him) used to say, “The people used to recite takbeer from the time they came out of their houses until the imam came in.”
The takbeer begins on the first day of Dhul-Hijjah and lasts until sunset on the last of the days of tashreeq (the three days after Eid).
الله أكبَرُ الله أكبَرُ الله أكبَرُ، لا إله إلا الله الله أكبَرُ الله أكبَرُ الله أكبَرُ، ولله الحمد
-Wearing the best of clothes
The Prophet (peace be upon him) had a cloak which he would wear on the two Eids and on Fridays. (Saheeh Ibn Khuzaymah)
Ibn ‘Umar used to wear his best clothes on Eid. Al-Bayhaqi
Males should adorn themselves, wearing the best of clothes and putting on perfume. However, women should avoid doing this while going out because Allah has forbidden them to show their adornment to any except her mahrams. If she wants to adorn herself at home, when only her mahrams are present, then there is no harm.
-Routes for the Eid prayer
It is mentioned in Bukhaari,986, that on the day of Eid, the Prophet (peace be upon him) used to vary his route. It is thus recommended to go for the prayer by one way, and return by another. Also, the Prophet went and returned walking.