The nice thing about rails is you get to be super creative with it, and while I can't say I've ben skiing rails for that long, I can tell you what I know:
1. Always look at the end of the rail
2. Always look at the end of the rule... (always gotta have a Fight Club reference.)
3. The worst mistake you can make is convincing yourself that you're good at rails because there is always someone (not just pros) whose way better, so having fun is key
4. Worry about style, more than on jumps, style can make an easy rail took look sick or a really hard one look stupid. I can't tell you how many terrible 450 ons I've seen, but I've also seen some insane tail slides (tail presses).
5. Go fast (it looks better once you're comfortable that is)
6. If you get it the 1st time congrats, if not hike until you get it, never say last try, and keep doing something after you get it the 1st time until you get it down.
7. Foot locks are everything, start them earlier than you think.
8. Don't be afraid to change your trick mid trick, sometimes it pays off.
9. Simple tricks are often the coolest looking ones (look at Paco Garcia's BS 270 out in T&S Days 2)
10. Watch snowboard videos, they'll give you an awesome outlook on skiing rails. The CASG edits are sick too.
11. Don't be afraid of anything. chances are if you can slide the box version of something, you can slide the rail version. (unless you have a really sketchy park then maybe b a little cautious)
12. Don't be a style jacker, be yourself.
13. the 4bi9 crew are the only ones who look good afterbanging. (sorry everyone else)
14. Know how sharp your edges are. And don't spend all day on rails as fun as it is. You'll learn so much from just skiing around in the "side country".
15. Have an Open Mind and Have fun.
Good luck man.