a) Know how to fall. If you don't, rails aren't for you. If you fall left, know how you'll do it. If you fall right, plan that out too. Casing on a rail is ZERO fun.
b) A lot of people go too slow thier first times on rails. Don't be chicken to have a bit of speed going in. Greasing a rail on non detuned-skis is not the easiest.
c) The more detuned your skis are, the easier it gets.
d) Avoid riding your edges. Though you will edge, once you break the 5-degree plane, your skis will go without your body under them.
e) Like the dude said, you HAVE to commit with your body. Commit to having your body centered on the rail as soon as you're touching it. Half-assing means you stand no chance.
f) Keep your feet 1-2ft apart. Everyone has a different style.
g) Start on something that's not far off the ground. If you want to get nutted, defy me.
h) Don't even think about curved rails until you got the straight ones down.
i) Look to start on Flat bars and/or double barrels. Don't start on single barrels...they're harder to learn on.
h) I'm spent..... that's my advice. Bring the pain.
The original Cliff Huck-stable