I am no expert either, but this is how I learnt: The approach:
A huge factor is going in straight, and jumping in the center of the jump. If you jump skew, it would be an awkward jump for both you and the horse. Another important thing is maintaining a consistent pace. When I trot towards jumps, I keep my leg off my horse (unless she's lazy), because she has an active trot and I keep her focused, calm and slow by gently playing with the reins to slow her if she speeds up, or I slow my posting. Then about 3 strides away I sit, as it helps me "feel her".
At a canter, once again straightness and a consistent pace are important. This time I keep my leg on, but I don't use it, because she has a slow lopey canter
And sometimes hesitates, and I will need to just give her a squeeze to encourage her. I keep my reins snug to hold her until the jump, but about two strides away, I lengthen them a smidge to give her her head to be able to take off.
I look at the jump just to get straight and centered, then I look straight again. I find that staring at the jump tends to make me freeze up. Take off:
At both trot and canter, when we get to the take off point, I give her a squeeze or a kick (depends on what height the jump is), and I make a noise of encouragement, such as a click, or I tell her "hup". It encourages her to tuck, and jump up rather than forward. For my release, I put my hands right behind her ears. It may not look pretty but it helps me to remember to release and it doesn't catch her in the mouth, and after a few jumps I can just move my hands halfway up her neck. I also swing my legs forward and "pin" it there so that they don't go backwards, and I go into two point with my heels pressed firmly down. And look straight Mid air:
In mid air I pull gently on the rein of which way I'm going to turn next, so that she lands on the right leg, but I keep my release. It's at this point that I start to look at my next jump, not down at her neck. Landing and going away:
I keep the release and two point for a half a stride after the jump, then I sit back (gently) and bring my hands back. I slow her if I need to, or speed her up if I need to. Then I head for my next jump, and redo the whole thing :)
And a good piece of advice I've heard is; If you don't back off from the jump, neither will your horse. Say to yourself; "I CAN do this, my horse CAN do this, so we WILL do it!"
Like I said, I'm no expert, but that's what I do... Hope it helps