Try to practice with no stirrups it really helps! Also my instructor once told me "imagine that you have a 50 euro note on the saddle. It'll blow away unless you keep your butt in the saddle!" And for some reason this helped alot!😂
Make sure you are putting your weight in your heels and not piniching with your knees. If you have your weight in your heels then you should be able to sit in saddle. One way to help get your weight in your heels plus improve your balance is two point when you are flatting!
Keep your calves locked and losses your thighs
Lunge lessons with no stirrups will help. Position is everything!
Pretend your Hula hooping. I know it sounds funny but it's what my trainer says and it actually works!
I have this same problem! I think it helps if you start with a collected canter and get really good at sitting the trot and the collected version of the canter..
Sit up straight and keep HEELS down!!
Relax and roll your hips under you alittle bit and sit alittle deep, but make sure you don't drive with your seat, just go with it
Support your back, use your core, and sit up straight
Make sure to lean back and keep your weight in the stirrups.
relax your hips and practice as much as possible
Try to move with the horse but don't squeeze with your legs and act like you are in a rocking chair, also riding without stirrups helps so much.
Totally agrees with what the others said but also maybe sure you relax your lower body and think about learning back and "sitting deep". But yeah lunging and no stirrups are really good exercises!
Sit back and try to sit as deep as you can. Perhaps having someone lunge you and you horse could help so then you can solely focus on your seat and position :)
Try to ride without stirrups it helps a lot !