One cause of bouncing the landings (like a pogo stick) is the nosewheel being too long in relation to the mains. After a few hard landings, the mains tend to spread out and the tail gets closer to the ground. You have to occasionally bend the mains back to bring the tail end up.

It will help also if just as the wheels are about to touch down, you start feeding in up elevator to see how long you can keep the nosewheel off the ground.