In regards to teaching the slide we do on a post rain day. We go to one of the athletic PE fields we have take a throw down and teach them how to slide. The kids love it because each coach MUST teach a slide. In regards to drills we incorporate it into base running. During live BP we have a base running group. The group is told they must slide on every other ball they go on. Below you will find how it works. The only place they do not slide is HP because we have a hitters mat.
Round 1: Sac Bunts (Feet First into 2nd base)
Round 2: Hit and Run (If on infield feet 1st into 2nd. If ball would have gotten through feet first into 3rd)
Round 3: Right Side (Head 1st into 3rd) I chose this to be the head first because this situation will never happen.(hasn't in five years of the drill). I feel if we were to do head first on Sac bunts for example you might get a player to sliding head first into second in a dangerous situation during a game.
Runners must also alternate their slides.
1st slide straight into the bag.
2nd slide on the inside of the bag with a reach
3rd slide on the outside of the bag with a reach