Shaykh Abdul-Aziz bin Baaz (may Allah have mercy upon him) answered: Salat Al-Istikhara is to be prayed in every affair of which you are uncertain. Is it more beneficial to do it or to leave it; this is the place of Istikhaara. As for something that is known to be good, then you don’t pray Istikhaara for that. For example, you don’t pray Istikhaara about “should you pray or shouldn’t you pray,” you don’t do that. The obligatory prayers are required and legislated. Like them, Zakat, fasting, Hajj, and fasting Mondays and Thursdays; you don’t pray Istikhaara for any of that because they are known. But, something about which you are confused, for example if you want to marry someone’s daughter and you are hesitant, then pray Istikhaara. Or somewhere specific to where you’d like to travel and about which you’re hesitant, is this travel beneficial for me or not; pray Istikhaara.
And like this the thing that about which you are hesitant or uncertain; you pray Istikhaara to your Lord. If you prayed two Rak’ah (units of prayer) for Istikhaara and asked your Lord, do what your heart is inclined to. If you’re inclined to one of the two things, then do it, it’s better.
It is recommended that you seek the advice and ask for the opinion of those good people that you trust after you repeatedly make Istikhaara. Ask your brothers, sisters, friends, and parents. Seek advice from those people you see to give beneficial advice so that they can contribute. Do whatever puts your heart at ease.