Alethia,
I learned to fly head down at 50 jumps with no coach. I just watched videos and got advice and basically taught myself. I got my first spock on a rodeo at 180 jumps and was turning points. I've got about 1000 jumps now and have taught a few people along the way. As everyone said "know thy altitude". That is #1. Other than that when I go to teach someone to freefly I tell them to do several jumps where they are not allowed to be on their belly before 5000. This will teach you to fly in many positions, becuase freeflying is not just sit or head down.
Being a good freeflyer means you are never unstable. Learn to be aware while being out of control. When starting to fly on your head I would recomend leaving the plane with the wind to your back upright and doing a lazy half back flip with your legs wide, knees bent, and arms in. Do this for several jumps until you feel you can hold a somewhat verical position. At that point its all about not shooting across the sky. The best way to tell is to jump with someone else, preferebly a coach. Relaxation is the key. Once you learn where vertical is I always recomend running in place after exit while transitioning to your head. This takes your mind off things and lets your body do its thing. You would be suprised how stable and still you are while doing this. As with anyother type of flying I recomend jumping with those worse than you, after you are proficient of course, this will teach you to be a better flyer instead of always jumping with those who make up for your mistakes. Good luck, be safe, and KNOW THY ALTITUDE(don't rely on a ditter)!!