a few points to keep in mind
1- the first and most important thing is to keep your weight centered, or even a little more on your front foot. This will help you stay over your board and control it better, which means you don't have to force anything.
Most beginners freak out when the board points down the fall line, and lean back. Its difficult to stand in that super-heavy-rear-foot kind of stance, much less make the board turn. So first thing is STAND OVER THE BOARD, you are riding it, not the other way around.
No matter how scary it may seem at first, standing over the board is the most natural position, and by far the easiest way to control it and keep from falling.
2- Turning should be pretty much effortless if you are standing properly on the board. An easy way to visualize toe-to heel turns is not in the feet, but your navel. When you are on your toes, your bellybutton should be pointing uphill. Just turn it downhill. If you are standing centered over the board, a small sustained twist in the direction you want to go is all you need.
You shouldn't have to twist unnaturally or forcefully, its just as if you are say, holding a tray of drinks on front of you, and twist your upper body to place the tray on a table beside you, without moving your feet.
(remember to quit twisting as soon as the turn is completed, and start linking the next turn, or else you may end up spinning a 360)
3- Timing. One more big problem beginners have is when to switch the edges. It is a very subtle movement that can be a bit difficult at first.
From your description, it seems like you can the the board to point down the fall line. Some people get excited because its here that you start to really pick up speed, and because its scary, they want to complete the turn as quickly as possible. So the end up cranking onto their heel edge to early or too much, and end up falling over.
If thats the case, go to a gentler slope to practice, where you don't pick up as much speed and can relax more thru the turn. Make your turns big, and edging slow and deliberate. Remember to edge with your heel as you try to get that bellybutton pointing downhill. If you do one without the other, is will be akward.
Hope that helps
King Shit of Turdville
Last edited by anti-bling; 11-25-2010 at 08:21 PM.