hehe i did giggle then when reading Cascaras post but totally spot on luv said so diplomatically!
Along side the thrusting encouragement keep the leg long and relaxed! outside leg slightly back inside leg on the girth little squeeze thrust and relax thrust squeeze relax once you have canter squeeze relax squeeze relax etc!but remember dont over think it! Imagine what you want the horse to do next, then do it! You may benefit from a private lesson on the lunge line with no stirups hun cause it will improve your balance! But you should consult your instructor and ask for their opinion if your not satisfied maybe move instructor or yard!