Praying Istikharah in all one’s affairs
Question

We often hear about Salaat al-Istikharah, but we only do it in rare cases. Is this correct? I hope you can explain to us.
Praise be to Allah.Salaat al-Istikharah is a means of achieving true submission [‘uboodiyyah] to Allah and focusing the Muslim’s heart on Allah, and freeing him from feeling attached to other created beings. 
Striving to achieve that in all vicissitudes of the heart and soul is the utmost submission, the perfection of putting one’s trust in Allah. That is when the person feels his need of Allah and finds joy and tranquillity in turning to the Creator, the Almighty, the Controller of affairs, so hardly anything happens to him, great or small, but he turns to Salaat al-Istikharah to seek guidance from Allah, may He be glorified and exalted. 
It was narrated that Jaabir ibn ‘Abd-Allah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings of Allah be upon him) used to teach his companions to pray Istikharah in all things, just as he used to teach them soorahs from the Quran Narrated by al-Bukhaari (6382).  
Al-Haafiz Ibn Hajar said in Fath al-Baari (11/184): 
The general meaning includes both major matters and insignificant ones. Perhaps an insignificant matter may result in something major. End quote. 
Al-‘Ayni said in ‘Umdat al-Qaari (7/223): 
The words “in all things” are indicative of its general meaning, and that a man should not regard anything as too insignificant because it is small and not pay attention to it, and thus not pray Istikharah or pray for guidance concerning it. He may regard something as insignificant but doing it or not doing it may lead to great harm. Hence the Prophet (peace and blessings of Allah be upon him) said: “Let one of you ask his Lord even with regard to his shoelace.” End quote. 
Thus it is clear that it is a mistake to limit Istikharah to rare cases or few issues. Rather the Muslim should turn to Allah and seek His guidance in all his affairs concerning which he is hesitant. Zaynab bint Jahsh (may Allah be pleased with her) prayed Istikharah when she received a proposal of marriage from the Prophet (peace and blessings of Allah be upon him), and al-Nawawi (may Allah have mercy on him) commented on that by saying in Sharh Muslim (9/224): 
This shows that it is mustahabb to pray Istikharah for the one who is thinking about doing something, whether the matter is evidently good or not. This is in accordance with the hadeeth of Jaabir in Saheeh al-Bukhaari: The Messenger of Allah (peace and blessings of Allah be upon him) used to teach us to pray Istikharah in all things.” And perhaps she prayed Istikharah because she was afraid that she might fall short with regard to his rights (peace and blessings of Allah be upon him). End quote. 
It says in Liqaa’aat al-Baab il-Maftooh by Shaykh Ibn ‘Uthaymeen (no. 85/question 1): 
Question: 
Are the two rak’ahs of Istikharah prescribed only with regard to matters where it is not obvious which is the right option, or should they be done concerning every matter one does, even if it is obviously good, such as becoming the imam of a mosque or proposing marriage to a righteous woman and the like? I hope you can clarify? 
Answer: 
Salaat al-Istikharah is done when a person is thinking of something and is hesitant about the consequences, so he prays Istikharah to Allah, i.e., he asks Allah for the better of the two options: going ahead with it or not doing it. But he should not pray Istikharah with regard to everything, meaning that if a person wants to eat lunch he should say, I will pray Istikharah about it, or if he wants to go and pray with the congregation in the mosque he should say, I will pray Istikharah about it. Rather he should pray Istikharah and ask Allah for guidance about things of which he does not know the consequences, such as becoming the imam of a mosque, if he is offered a position as imam of a mosque and does not know whether it is better for him to become imam or not. So he should pray Istikharah, because being the imam is good in and of itself, but with regard to the consequences, he does not know whether he will be able to fulfil the duties of being imam or not, or whether he will be able to settle in this mosque or not, or whether he will be suitable for this congregation or not, so he is not asking for guidance about becoming an imam with regard to whether it is good; rather he is praying for guidance as to whether it  is better in terms of consequences. How often does a man become imam of a mosque then he gets tired and does not do his duty, and problems with the congregation make him wish that he had not become imam. The same applies to marrying a righteous woman; he does not know what the consequences will be. 
What matters is that in all cases where you are hesitant or uncertain, you must turn to Allah and ask Him for the better of the two options. End quote. 
See also the answers to questions no. 11981 and 2217. 
And Allah knows best.