To maximize your potential you must know your presentation inside and out. In sales, as in sports, we say, "get back to basics". It comes down to practice, practice, practice. Or...Peat, Repeat, Drill for Skill.
Knute Rockne, when he was coaching at Notre Dame, gave a talk to a large sales organization. The heart of his speech was that you must must hold the ABCs of your job so firmly in your mind that they become part of you. You've got to drill, drill, drill.
So let the brothers Peat and Repeat be your friends. You will see the payoff in your sales career.