Another leg exercise on the trampoline is to keep extending out one leg at a time, without locking your knees. This targets your quadriceps, like the leg extension machine does.
You can jump while extending out one leg at a time. This targets your adductor muscles.
One simple, great trampoline leg exercise to do is to run in place. If you focus on keeping steady and not bouncing too much, you will work extra hard to bring your legs back up in a greater range of motion. Try not to let the increased momentum of the jump be what keeps you going.
My third book, Pocket Guide to Fitness, is available on http://www.authorhouse.com and http://www.amazon.com. If you look up my name on those Web sites, you will find my other books The Boy in a Wheelchair and Life, Work and Play: Poems and Short Stories. These two books are on my Web site http://www.louizapatsis.com.