Expressing joy on Eid is one of the acts of worship by which the Muslim draws closer to Allah. The way we do it is by offering congratulations to other people.
The etiquette in Eid ul-Fitr (Eid) 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, “Taqabbala Allaah minna wa minkum.” (Ibn Hajar said, its isnaad is hasan).
Offering congratulations was something that was well known among the Sahabah, and scholars such as Imam Ahmad (may Allah have mercy on him) and others allowed it. There is evidence which suggests that it is prescribed to offer congratulations and good wishes on special occasions, and that the Sahabah congratulated one another when good things happened, such as when Allah accepted the repentance of a man, they went and congratulated him for that, and so on. Undoubtedly these congratulations are among the noble characteristics among the Muslims.
Adorning Oneself on the Occasion of Eid.
It was narrated that ibn Umar (may Allah be pleased with him) said that Umar took a brocade cloak that was for sale in the market and brought it to the Prophet of Allah (peace and blessings of Allah be upon him), and said, “O Messenger of Allah, buy this and adorn yourself with it for Eid ul-Fitr and for receiving the delegations.” The Prophet of Allah (peace and blessings of Allah be upon him) said to him, “Rather this is the dress of one who has no share (of piety or of reward in the Hereafter)…” (Narrated by al-Bukhari).
The Prophet agreed with Umar on the idea of adorning oneself for Eid, but he denounced him for choosing this cloak because it was made of silk.
It was narrated that Jabir (may Allah be pleased with him) said: “The Prophet (peace and blessings of Allah be upon him) had a cloak which he would wear on the two Eids and on Fridays.” (Narrated by Ibn Khuzaymah)
So a man should wear the best clothes that he has when going out for Eid. With regard to women, they should restrain adorning themselves too much when they go out for Eid, because they are forbidden to show off their adornments to non-mahram men. It is because it is forbidden for a woman who wants to go out to put on perfume or to expose men to temptation, because they are only going out for the purpose of worship.