There are several things to think about here. First, research shows that video feedback is a valuable learning tool. Combining self-video with videos showing experts doing the task may be the best way to change one's own methods of doing something and improve the technique.
So, first get a baseline of your athletes; videotape them making jump-landing shots. Catch the action from all angles and even from above if you can. Choose one key area to work on. Say for example, you want the athlete to work on softer landings. Provide an "expert" video showing how to land a jump.
Narrate the tape and give the athlete a checklist of things to work on:
Land with both feet at the same time.
Land with the knees in neutral (not rolled in or out). Land with feet shoulder-width apart. Land on the forefoot and roll the weight toward the back of the foot.
Use just the right amount of hip and knee flexion (more than 20 degrees on contact with the floor).
Tell each athlete that the goal is landing as softly as possible. Having the athlete view his or her own videotape is a good way to analyze his or her own performance. This teaching tool increases the individual's involvement in training.