Most of the common mistakes are rushing things. Take your time. With a muzzleloader you normally get one shot so there is never a need to hurry. Swab the barrel the same each and every time. Be consistent with everything you do. That is the best way to get the most accuracy out of the rifle.. Also do not let other people interfere with you. Keep your mind on what you are doing all the time. I am sure you are going to have a lot of fun and the rifle will shoot well. Keep us posted on how the rifle does for you.