1 Question: Has Istikhãra any basis in the Shari‘a? Is there a problem in repeating the Istikhãra [for the same intention] by paying alms [before it] in order to get a guidance that is to one’s liking?
Answer: One may resort to Istikhara in situations where he is confused and cannot prefer one side [of the issue] to the other, after having pondered over it and having consulted [those who know about it]. It is not Haram to go against the Istikhara, though it may cause one to be regretful. Repeating the Istikhara is not right, unless it is for a different issue, similar to if one pays alms (Sadaqa) and continues with the same situation.sistani.org/15221
2 Question: When is it good or necessary to perform an Istikhara?
Answer: Istikhara is done when you are confused and perplexed. One must first of all consult experts or wise individuals to see if he can reach a decision. If after seeking experts' advice he still remains confused, he can then do Istikhara. You must know that when an act is good in itself, there is no need to make Istikhara for it.The best times to perform Istikhara is after the obligatory or recommended prayers, and also before sunrise on the blessed day of Friday.sistani.org/15222
3 Question: I am a girl who has received many proposals for marriage but each time my father has done istikhara and it came out "bad". What should I do? Should I keep waiting until the istikhara comes out "good"?
Answer: The woman and her guardians should give importance to the qualities of the man she chooses to marry. She should not marry except a man who is religious, chaste, of good character, not a drunkard or someone who commits sins and evil deeds. It is better not to reject the proposition of a man who is religious and of good character. The Prophet has said, “When a man whose religion and character pleases you comes to you [with a proposition], then marry him. If you do not do so, there will be chaos and a great corruption in the world.” It is not good to rely on Istikhara when he/she can do research about the character and background of someone who comes with a proposal.sistani.org/25551