The way of using the law of belief is first to work on your negative thoughts. You need to find a way to belief the reality of the thing you want tob e, to have or to do. God knows this is not easy, you may also consider getting professional help like a counsellor, therapist depending on how deep the negative feelings are manifested in you. Once you are able to find a way to convince your mind that you already do, or that you already are, or that you already have the thing you want – you are all set to experience the positiveness of the law of belief.