Praise be to Allaah.

Salaat al-Istikhaarah is a means of achieving true submission [‘uboodiyyah] to Allaah and focusing the Muslim’s heart on Allaah, 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 Allaah. That is when the person feels his need of Allaah 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-Istikhaarah to seek guidance from Allaah, may He be glorified and exalted. 

It was narrated that Jaabir ibn ‘Abd-Allaah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) used to teach his companions to pray istikhaarah in all things, just as he used to teach them soorahs from the Qur’aan 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 istikhaarah 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 Allaah 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 istikhaarah to rare cases or few issues. Rather the Muslim should turn to Allaah and seek His guidance in all his affairs concerning which he is hesitant. Zaynab bint Jahsh (may Allaah be pleased with her) prayed istikhaarah when she received a proposal of marriage from the Prophet (peace and blessings of Allaah be upon him), and al-Nawawi (may Allaah have mercy on him) commented on that by saying in Sharh Muslim (9/224): 

This shows that it is mustahabb to pray istikhaarah 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 Allaah (peace and blessings of Allaah be upon him) used to teach us pray istikhaarah in all things.” And perhaps she prayed istikhaarah because she was afraid that she might fall short with regard to his rights (peace and blessings of Allaah 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 istikhaarah 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-istikhaarah is done when a person is thinking of something and is hesitant about the consequences, so he prays istikhaarah to Allaah, i.e., he asks Allaah for the better of the two options: going ahead with it or not doing it. But he should not pray istikhaarah with regard to everything, meaning that if a person wants to eat lunch he should say, I will pray istikhaarah about it, or if he wants to go and pray with the congregation in the mosque he should say, I will pray istikhaarah about it. Rather he should pray istikhaarah and ask Allaah 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 istikhaarah, 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 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 Allaah and ask Him for the better of the two options. End quote. 

See also the answers to questions no. 11981 and 2217. 

And Allaah knows best.