Replying to How to "act" when jumping on big jumps

Hello every1.
I bought twintips last winter, and startet praccing in park on jumps, rails etc. Now I am trying to take one step further in jibbing. But I have one problem. I always fall when trying to jump on the bigger jumps (which probably you describe as mid-size jumps). I really don't know how to interact when I'm in the air, and my arms keeps going to each side, and I really do not have any ctrl. It's like I am really nervous or scared when I'm in the air. I also keep the same position as when I "take off" from the jump, so it's like I lean backwards, and don't how to lean forward, but if I try to lean forward it goes very wrong. So I need some advices here!

Thanks NS