I forgot one extremely important part!
Look beyond the fence. Do not look down, this will make you unbalanced and in many cases people tend to get more insecure about the fence and/or height :)
Keeping your heels down is by far one of the most important things when it comes to getting a good position. It's about distributing your weight right. Yet you're not supposed to push your heels down as far as you get them; you're supposed to put the weight on your stirrups. Don't let your legs slip behind or forward! There's supposed to be a line between your heels and your hips. By doing this, you'll get a lot more balanced.
How much you're gonna lean forward depends on the height of the obstacle. If it's a small obstacle (ex 1m) you don't have to lean that much forward. But as you keep on jumping and working with your position, you'll do it automatically :)
Hope this helped you somehow!😌
Try practicing going around in the arena at the walk in proper two-point position. Then after practice in trot and do it regularly. For example at the beginning and end of your ride
Don't let your legs slip back, it is something most people don't realise they do but it is a bad habit
press down onto ur heels and keep your back straight