What is the best time for Salatul-Istikhara, and is it permissible after Salatul-Witr?

There is no specific time for the الاستخارة (guidance-seeking) prayer, and the person performing it should avoid praying during the prohibited times. It is preferable to choose virtuous times, such as the last third of the night. It should not be prayed after the Witr prayer, based on the Prophet's (peace be upon him) saying: "Make the last of your prayers at night Witr."