Keep your heels down when you start to fall
Always have your weight back and downwords. When you keep your heels down, let them hang down do not push them down or you will push yourself out of your saddle
Lots of bareback practice and even jumping bareback can definitely help your balance and staying even for when you get back in the saddle!
I used to fall off a lot, so my trainer changed my saddle so that it has knee rolls, so maybe you can change you saddle ( if you don't have a saddle with knee rolls)? And also if/ or when you have knee rolls squeeze with your knees
If it was bucking open your inside rain and sit back with your heals down.
Just more hours in the saddle! Perfect practice makes perfect riding! So try to keep lots of hours in the saddle that's all
If it was bucking heels down sit back
Maybe Try to squeeze your nes in the saddle