How to pray salat al-Istikharah ?

When you wish to pray Salat al-Istikharah, you first pray two Rak’ats. These must be optional or sunnah prayers, so not the 5 daily obligatory prayers.

After praying these two optional Rak’ats, you perform the following Du’a:

(Sorry I could not copy paste the Arabic, Tumblr mixed everything up somehow)
Allaahumma ‘innee ‘astakheeruka bi’ilmika, wa ‘astaqdiruka biqudratika, wa ‘as’aluka min fadhlikal-‘Adheemi, fa’innaka taqdiru wa laa ‘aqdiru, wa ta’lamu, wa laa ‘a’lamu, wa ‘Anta ‘Allaamul-Ghuyoobi, Allaahumma ‘in kunta ta’lamu ‘anna haathal-‘amra-[then mention the thing to be decided] Khayrun lee fee deenee wa ma’aashee wa ‘aaqibati ‘amree - [or say] ‘Aajilihi wa ‘aajilihi - Faqdurhu lee wa yassirhu lee thumma baarik lee feehi, wa ‘in kunta ta’lamu ‘anna haathal-‘amra sharrun lee fee deenee wa ma’aashee wa ‘aaqibati ‘amree - [or say] ‘Aajilihi wa ‘aajilihi - Fasrifhu ‘annee wasrifnee ‘anhu waqdur liyal-khayra haythu kaana thumma ‘ardhinee bihi
O Allah, I seek the counsel of Your Knowledge, and I seek the help of Your Omnipotence, and I beseech You for Your Magnificent Grace. Surely, You are Capable and I am not. You know and I know not, and You are the Knower of the unseen. O Allah, if You know that this matter [then mention the thing to be decided] is good for me in my religion and in my life and for my welfare in the life to come, - [or say: in this life and the afterlife] - then ordain it for me and make it easy for me, then bless me in it. And if You know that this matter is bad for me in my religion and in my life and for my welfare in the life to come, - [or say: in this life and the afterlife] - then distance it from me, and distance me from it, and ordain for me what is good wherever it may be, and help me to be content with it.

Also, after or before performing this prayer, there is nothing wrong with asking for advice from your fellow believers. For Allah says:

"And consult them in the affair. Then when you have taken a decision, put your trust in Allah." [3:159]

Furthermore, Salat al-Istikhara can be performed multiple times and to the best of my knowledge there is no limit for performing Salat al-Istikhara. Sometimes a person receives an immediate answer, other times it may take some time.