Cal hops for girls are pretty easy to teach if they have strong cast hand. I usually start off with forward roll straddle hand to block and grip change. Then we'll do some floor bar work with kick hand and block change the grip. But you really don't need to do that stuff, you just need to hand spot the skill and make sure that they get a strong push through the shoulders and they catch the bar.
If you want drills for hop fulls thats will take me a long time to type out so lemme know.
I learned the grip change/catch by jumping to HS from a mini tramp under the bar (and doing the hop), which makes it a lot easier. But after that, getting over just took trying it a bunch of times to get the timing. I always did it on the low bar though into a pirouette. I think it would have been easier on the high bar because I cast better out of a long hang kip. But I never had a reason to do it on the high bar in any routine or anything.