"Trust in the Lord with all thine heart; and lean not unto thine own understanding. In all thy ways acknowledge him, and he shall direct thy paths." - Proverbs 3:5-6
This is one the scriptures I remember from Seminary and it was pretty easy to memorize. I remind myself on a daily basis that I need to counsel with the Lord often so that I make the correct decisions; or say the right things.
Leaning on the Lord is a humbling act. We are human and we make mistakes. We don't know everything and we should not pretend to know everything. :)
When we depend on the Lord and we seek his guidance we open are hearts to understanding. Discernment starts in the heart and moves up and enlightens the mind. He wants us to use our mind to reason, but He wants us to reason in a way that lines up with his will.
In the Doctrine & Covenants we are reminded that we must first study it out in our minds and then go to the Lord asking what his will is. We should go to him with a plan and ask him if it be right. When we are open to his answers we will be able to recognize the correct path. Sometimes the answer will be no. Other times it will be not yet. And still other times we will receive an affirmation.
When we receive answers from the Lord we should feel confident in our deeds and actions know that what we say and do is pleasing unto Him.