Standing helps to open up the space for breath support, so stand up, Brett, and FORGET about your hands. Don't clasp them behind your back, just relax. If you need to think about holding them a certain way, or if they are shaking to make you noticeably nervous, bring them up together in front of you in some relaxed way, touch the fingertips together or lightly lace your fingers together to stop the shaking, but however you hold them or if you place your hand against your chest, or let them relax by your side, don't focus on it. Focus on the meaning of the words, and you will eventually find that your hands will unconsciously do what you do when you are talking. When you stand and talk to a friend about something, when you are relaxed, you don't think about your hands. You just need to get to that same comfort zone when you are singing.