I work with a lot of kids of all levels, from some high schoolers who take the short bus, up to college football players, however mostly in a one-on-one or small group basis.
I’ve seen coaches better than me who can teach 10 year olds to do Olympic movements. But I find the idea of doing a clean very hard to grasp for most people of any age. First you tell them, slow down, lift a weight you can manage, feel it in the appropriate muscle. Then you teach a clean and you’re like, thats it, explode! Result is confusion. Some kids can do a clean the first day. Others will do flying reverse curls all afternoon. So I build up slow. Every one can do a barbell shrug. Most can do an upright row. Now do an upright row, lifting the weight off the floor. Etc, etc, power shrugs, high pulls, push press, when they do these exercises a few weeks on each, suddenly, Mr. (Ms.) Flying Reverse Curl will pick up the weight, and do a hang clean, then wonder what the problem was. When you write the program, have Level I = Power Shrug II = High Pull III = Hang Clean so that the kids wil l all be doing the clean motion where indicated, but some will be on higher levels than others.
I think squats are easy to teach. You have them squat to a bench or box and sit on it. Use a broomstick or something for a bar so their hands are where they should be. Then you have them touch the box with their butt and come right back up, don’t put weight on it. Then do it with out the box. The only people who cannot do this are tall, lanky kids and/or those who lack ankle flexibility. You can recognize what’s going on, because they try to sit back to below parallel, but their heels lift off the ground. A lot of stretching the calf and practicing squatting down with minimal load until the heel lifts will correct this. I’ve also heard of squatting to a box or putting a board beneath the heels. Up to you and your beliefs. Another common problem is shaky knees, which are almost always weak thigh ab/adductors. Very minimal work will correct this. If you lack the inner/outer thigh machine, have them squeeze a basketball between knees while seated, then do that “aerobic class” exercise where they lay on their side and lift their leg up.
As far as splits, Monday Bench/Squat/Assistance
Wednesday Clean/Back (Row or Chinup)/Assistance Friday Incline/(trapbar/stiffleg/regular)Deadlift/Assistance seemed to work well as a starting point. I think 4 day a week is a lot for in season athletes. For out of season athletes chest/shoulder/tri legs/back/bis off, repeat off off, or upper lower off upper lower off off is ok too. I hope my answer helped. If you have any other questions, ask and if I can give any suggestions I will.