Take counsel in the matters faith demands of you with one who has the following five qualities: intellect, knowledge, experience, good counsel, and precaution. If you find these five things in a person, then make use of them, be resolute and rely on Allah. This will lead you to what is correct.
As for matters of this world which do not pertain to faith, make decisions about them and then do not think about them further. If you do this, you will obtain the blessings of livelihood and the sweetness of obedience.
Knowledge is obtained through consultation. The man of intellect is he who derives new knowledge from consultation, and that guides him to obtain his goal. Consulting a proper counsellor is like reflecting upon the creation of the heavens and the earth and the destruction of both, since the more intense a person's reflection upon these two things, the deeper he penetrates into the seas of the light of gnosis and the more he increases his understanding and certainty.
Do not take counsel from someone when your intellect does not give him any credence, even if he is famous for his discernment and scrupulousness. When you take counsel from someone your heart trusts, do not disagree with what he advises even if it is contrary to what you want. Surely the self combines both acceptance of the truth with what is opposed to it - that is, on receiving other truths which are clearer to him. Allah has said,
وَشَاوِرْهُمْ فِي الأَمْرِ
وَأَمْرُهُمْ شُورَى بَيْنَهُمْ
that is, they consult each other about it.