We are teaching our first-year lv3's front hips right now... it is going ok. We have ~8 girls and half of them have made their front hips within about a month of concentrating on it.
We are making the front hip our priority on bars because we think it's the most difficult skill to attain for L3 bars. We basically do 2 drills on a regular basis.
1. from high-support on bar: fall forward in straight/hollow position. we have a theraband set up behind them so it catches their ankles at about 4 o'clock.
2. tie them to the bar with a bungee so they can do a bunch of front hip circles easily... it's a pain to tie them in and out, but they get so many turns. you don't have to spot and it's great for targeting the wrist shift which imo is hard to drill in a way that actually feels like the kipping wrist shift.
Then I also spot them - I'm currently spotting them through the entire Lv.3 routine for shaping purposes (and safety for that squat-on) daily... the weaker front hip circlers get more reps and the stronger front hip circlers are spotted on the full connection: front hip into cast into squat-on.
One variation that I'm a fan of and has worked for me in the past is a tucked front hip circle - it's super easy to wrap the bar this way and I've never had trouble switching them to straight legs once they figure it out.