What is the Istikhara prayer?
If you are unsure about a decision you have to make, there is a specific prayer that you can do to ask for Allah's help in making your decision. This prayer is called Salaat-ul- Istikhara (Prayer of guidance).
Istikhara is Sunnah and should be performed for all permissible acts which are not obligatory i.e. Salaah. Meaning one cannot perform Istikhara to see whether they should pray their Salaah five times a day or not, because Salaah is a direct obligation and an order from Allah. In the same way Istikhara cannot be done to see whether they should do something Haram or not.