The key is to be quiet.
It's not that your mind has to be quiet. It's you who needs to be quiet. The minute you stop putting your whole heart and soul into the mind as if it were your savior and protector, you will find yourself behind the mind watching it. That's how you know about your thoughts: you are in there watching them. Eventually, you will be able to just sit in there quietly, and consciously observe the mind.
You can watch the mind being neurotic and not get involved. Withdraw your attention from it, and the thinking mind falls away. Start with the little things.
For example, you are walking along and you see a friend. You say hello but the friend keeps on walking by. You don't know whether they didn't hear you or if they actually ignored you. You aren't sure what's going on. Your mind starts going a mile a minute. Good time for a reality check! There are billions of people on this planet, and one of didn't say hello to you. Are you saying that you can't handle that? Is that reasonable?
Watch the mind try to figure out what to do about it. Just marvel at the fact that all of this is going on inside simply because someone didn't say hello to you. Just watch the mind talk, and keep relaxing and releasing.
Begin this journey to freedom, by reminding yourself to observe the mind. This will keep you from getting lost in it.
From the Untethered Soul, Michael Singer