Same situation here. I drill drill drill. Minimum spotting required. These are at a speed where I can spot by tapping or grabbing problem areas without risk to myself or the gymnast.
First drills:
Step ro on a line
3 step ro on a line
Handstand pike down, fall back onto bottom with straight legs (8inch mat)
Handstand snapdown, fall back onto bottom straight legs (8 inch mat)
Backwards jumping drills onto a large mat
Backwards jump onto a large mat, as soon as they land grab ankles and try to pull them apart to check tightness.
After they can do the ro's with a straight leg rebound:
Step ro rebound backwards onto mat
3 Step ro rebound backwards onto mat
Spotted backhandsprings on a wedge, fall onto bottom with straight legs (8inch mat)
Spotted backhandsprings on a wedge to handstand pikedown fall onto bottom straight legs (8inch mat)
Handstand snapdown spot bh to handstand, pike down, fall on bottom straight legs (8inch mat)
Spotted backhandsprings on 8 inch mat
Step ro on tumble track + 3 step ro on tumble track, straight leg rebound
After they can Do the above proficiently:
Spotted backhandsprings on the tumble trak (they usually have no problem doing these on their own very shortly)
2 standing bh's (spotted at first)
Step ro rebound (count to 3) bh (by themselves)
3 step ro rebound (count to 3) bh (by themselves)
Step Robh (spotted)
3 step robh (spotted)
By the time they get to the 3rd set of drills, their straightness and stepping habits should be consistent enough to know what to expect. If they can do the the whole thing together just fine while being spotted, I tell them. Then I wait until they ask me not to spot them to back off. It's worked so far!
For tucks, I generally do them at the end of the tumble track into the pit. As they get better, I add a 4 inch mat to stick a landing on. After that, punch tuck. Then punch tuck land on the tumble track, followed by doing them off a block (on the floor) to a 8 inch mat. Sometimes I use vault boards for front tucks to a 8 inch mat. Jump from block, to springboard, punch front. I don't do back tucks with gymnasts who can't backhandspring. After they have both a tuck and a backhandspring, I find they are consistent and confident enough to play with shape and set with minimal spotting. I always start back at the tumble track and build up the landing surface gradually though.