The hardest part of doing a good leap is taking off straight and in good posture. This drill work provides a good start.
Do a series of one foot hops the length of the floor ex mat (on a line) and whoever breaks for or loses balance has to repeat 3x. Do left foot, right foot, both feet, and sideways however you can. Add variations of leg positions...... like leg held up in front, or leg held up behind. When you become impressed with the way the kids are working and displaying their ability, it's time to add the leg actions, like split, switch, side split, or whatever.