These are many; among them is what is recommended by the Prophet (S) who has said: "Whoever prays two rek’as on Lailatul-Qadr and recites the Fatiha once in each rek’a and the Tawheed seven times, then when he finishes he seeks forgiveness seventy times, then he adds, ‘I seek Allah's forgiveness and to Him do I repent,' by the time he leaves his place, Allah will have forgiven him and his parents and sent angels to record good deeds for him for another year, and He would send angels to plant trees for him in Paradise and build him mansions and draw rivers, and he would not leave the life of this world before seeing all what is in store for him in Paradise."
Another recommended deed is ghusul (ceremonial bath) which is highly recommended and emphasized especially during the last three nights (of the month), and the best time to take it is after sunset prayers. And speaking of ghusul, it is recommended, as the Prophet of Islam (S) had himself done, to stay away from women during these most sacred days but to approach them in the first 20 days.
As a matter of fact, p. 180, Vol. 4, of al-Kulayni's Al-Kafi, p. 348, Vol. 94, of al-Majlisi's Bihar al-Anwar, and p. 112, Vol. 2, of Ibn Babawayh's work Man la yahduru al-faqih all suggest that it is highly recommended to approach women particularly during the first nights of the month of Ramadhan. These classic books quote the Commander of the Faithful (as) saying that it is recommended for a believer to cohabit with his wife (particularly) during the first night of this sacred month.
Another recommended deed is what is called the "plea by the sanctity of the Holy Qur'an" which is reported on the authority of both Imams al-Baqir and al-Sadiq, peace be upon them, who have said, "You must take the Holy Qur'an during those last three nights of the month of Ramadhan, open it, then put it on your hands and say: ‘Lord! I plead to You by Your revealed Book and everything in it, and in it is Your great Name and the most sublime attributes. I plead to You to send blessings unto Muhammad (S) and the progeny of Muhammad (S) and to free me from the bondage of the fire,' then you ask Allah whatever you wish."
Imam al-Sadiq (as) is quoted saying, "Take the Holy Qur'an, put it on your head and say, ‘Lord! By the grace of this Holy Qur'an and to whom You have revealed it, and by every believer You have praised therein, and by Your right upon them, for none knows Your right more than You!'
Then you repeat ten times each of the following: ‘By Your Grace, O Mighty God! By Muhammad, by Ali, by Fatima, by al-Hassan, by al-Hussain, by Ali ibn al-Hussain, by Muhammad ibn Ali, by Ja’far ibn Muhammad, by Mousa ibn Ja’far, by Ali ibn Mousa, by Muhammad ibn Ali, by Ali ibn Muhammad, by al-Hassan ibn Ali, by al-Hujja (al-Mahdi),' then you state your plea, and Allah will help you attain your objective if He pleases." Another special invocation quoted from the Prophet (S) says:
"I bear witness that there is no god but Allah, the One and Only God, without a partner, and that Muhammad (S) is His servant and messenger. I bear witness that Paradise is right and that the fire is right, and that the hour is approaching, there is no doubt about it, and that Allah shall bring life to those in the graves. I further bear witness that the Lord is my God: there is no partner with Him, nor a son, nor a father, and I bear witness that He does whatever He pleases and is able to do everything and is the Doer of what He wills.
He humiliates whomsoever He wills and raises whomsoever He pleases, Owner of the domain, Sustainer of the servants, the Forgiving, the Mercy-giving, the Omniscient, the Kind. I bear witness again and again and again and again and again and again and again that You, Lord, are exactly so and even more, and that none can describe Your greatness. Lord! I pray You to send blessings unto Muhammad (S) and the progeny of Muhammad (S) and to guide me and not to leave me to stray after having guided me, for You guide whomsoever You please."