The trampoline is made for bouncing, and there is more than one way you can do this. First of all, you should make sure that you are bouncing in the center of the trampoline, so that you can keep your balance and avoid falling off the device. The check bounce should be your first new skill, which will help you regain your balance by making it easier to reposition yourself in the middle of the trampoline. To do the check bounce, land on your knees rather than your feet. This will be easier if you bend your knees in the air as soon as possible when jumping.
The way your arms move is quite important in the proper performance of trampoline tricks. When you're lying flat on the trampoline, you need your arms to lift yourself up into a standing position. Your arms will also need to be in place for the seat drop, which is when you jump in the air and land sitting down.
The front drop is another fun trick, but you will have to be careful in aligning your body so you don't injure your back when you land. It's a good idea to first practice with the hands and knees drop, wherein you land with an even distribution of weight between your knees and hands.
A good place to find tips and advice about trampoline tricks online is the USA Trampoline and Tumbling Association, where you can see pictures of the jumps being performed. Another good site is Funspot.com which offers tutorials on tricks and stunts that you can do on your trampoline at home.