Depending on the gymnasts ability/confidence and the coach's own confidence, there are quite a few drills I've used in the past.
Straddled leg lifts - Lift legs past shoulders
Japana (Sitting in straddle, stomach on the floor) This can also be done with both feet raised.
Straddled swinging. This is quite difficult at first as the gymnast has to work out how to get the momentum. The idea is that they lift their bottom upwards.
Straddle press to handstand
Metal bar in gloves and loops:
1. straddled sole circles (feet on bar) I normally set up a coaching block infront of the low bar, and stand on it facing the gymnast. As the gymnast's bottom swings towards me, I grab their hips and help them to get back on top of the bar. I repeat this until they can do it on their own, which doesn't take too long at all.
2. Straddle on to the bar, and lift feet off so that the gymnast is balanced in a straddle lever, tell them to drop their shoulders backwards and their feet behind their shoulders. This is where the straddled swing mentioned in conditioning comes in useful. The gymnast needs to lift their bottom up whilst dropping their shoulders backwards and keeping their feet back behind their shoulders. As they get their bottom above the bar,Tell them to place their feet back onto the bar, so they finish in the straddle on position. As they get better at this drill they can do numerous repetitions. Same supporting technique as the previous drill, just be careful as beginners tend to forget where their feet are supposed to be!
3. As number 2, but cast straight into the stalder (miss out the straddle on phase) At the end of this drill you could begin to lift the gymnast to handstand rather than going back to feet on the bar. Timing is important with this drill, especially in the later stages when going up to handstand. It is a common mistake that the gymnast comes out of the straddle too early.
4. As number 3 from a higher cast and finally from handstand. The straddle should happen quickly and should stay 'close' to the bar.
The gymnast needs to learn to pull on the bar as she swings underneath, so that the bar helps with the end phase by 'rebounding' (can't think of the right word!) the gymnast upwards.
Next repeat all of the drills on the wooden bar!
I'm pretty sure I've forgotten something, if I remember anything I'll add it later!