Shafaqna (International Shia News Agency) – The Grand Ayatollah Sistani answered some questions regarding Istikhara. According to Shafaqna the questions and answers are as follows:
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 istikhãra (albeit with the intention of rajã’an) 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]. Repeating the istikhara is not right, unless it is for a different issue.
Question: When is it good or necessary to see 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 consultation 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.
Source: Ayatollah Sistani