Fasting . on this day has many rewards,as reported from Imam Sadiq (peace be upon him) that fasting on this day is expiation of sins of 60 years.
Ghusl. Shaykh Shahid Awwal says it recommended to take a Ghusl on this day.
Repentence / Asthagfa'ar- The blessed night of 'Arafah is the night of praying for granting all requests. Repentance at this night is accepted, prayers answered, and acts of worship and obedience achieve the reward of 170 years of worship.(the book of Ahmad ibn Shazan)
Ziarat Imam Hussain(as)-
Dua Ya Shahida Kulle Najwa-It has been reported from Imam Sadiq (peace be upon him) who narrated that the Holy Prophet (peace be upon him and his family) for `Arafah Night
Dua - Allahumma Man Ta'ba Tahaya- Shaykh al-Tusi, Sayyid Ibn Tawus, al-Kaf`ami, and Sayyid Ibn Baqi have recorded that it is recommended to say the following prayer on Fridays and at Friday nights and on the day and night of `Arafat (the ninth of Dhu’l-Hijjah).The supplication is as quoted from Shaykh al-Tusi’s book of al-Misbah
Night of Martyrdom anniversary of Muslim ibn Aqeel (peace be upon him) Ziyarat Muslim Ibn Aqeel
Ziyarat Hani Ibn Urwa
Day of Arafah Aamal