Just master the basics at first. Kneeling jumps, box jumps, seated box jumps, braod jumps, etc. You don't need to go ballistic on weights and variaitons Establish some max's on stuff like kneeling braod jumps (for distance) and box jump heights. Then start adding in more complicated stuff like 1-2 feet kneeling broad jump, land, then jump to a max box height. Unloaded depth jumps and reactive depth jumps are good places to start once you have all of your basic jumping down.
Personally, I do something explosive, not always reactive, every day. I figure that if at any point in my life I can't jump from my knees to the with relative ease, then I am either doing something terribly wrong in my taining or I am seriously injured.