Supererogatory prayers at night are done two by two, and when you are afraid that dawn is about to break, pray a single rak'ah for a witr (odd), and make your last prayer witr.

When half of the night or a third of the night had passed, he mentioned that Allah descends and says: Who calls upon me so that I may respond to him? Who asks me so that I may grant him? Who seeks my forgiveness so that I may forgive him? Until dawn breaks.

The best fasting after Ramadan is fasting in the month of Al-Muharram, and the best prayers after the prescribed -or mandatory- prayers is prayers at night.