Istikharah is like any Du’a’: if Allah, the Almighty, accepts it, He will make it easy for the supplicant and guide him to the best. And if He does not accept it then it will be like any unanswered Du’a’. It’s possible that Allah delays the reward for the person in the Hereafter, which is good for him/or her. However, people are always in a hurry, whereas something bad might be looming large and Allah, the Almighty, warded it off by the virtue of that Du’a’. 

After performing Salatul Istikharah , one should consult wise people and assess the situation to see how it might affect his deen (religion) and dunya. (life). Then he should choose the one that seems to be more beneficial, having firm belief that Allah will either bless his decision and make it easy for him to achieve what he desires, if it is good for him, or Allah will place obstacles in his path in order not to achieve what he desires. In the latter case, the person should be satisfied with the outcome, whatever it is, and commit his affair to Allah hoping for reward in the Hereafter. He should know that Allah does not decide except through His Divine wisdom and truth, even if it does not seem to us this way. Glory be to Him! We only know what He has taught us. 

Anyway, one who seeks Allah’s guidance through Istikharah will never be disappointed, as Allah will guide him or her to that which is good, except those who have violated the rights of Allah; they should blame none but themselves. It is stated in the Hadith: “Keep your commitment to Allah and He will protect you.”

http://www.onislam.net/english/ask-the-scholar/acts-of-worship/prayer/supererogatory-prayers/175483.html

http://97.105.52.213/en/artical/25496/signs-response-salatul-istikharah