i think its essential to start out with the basics.  get like a 25 foot or so flat rail, and nice 25 foot flat box too.  then get like a flat down box/rail, a couple of different rails and boxes after that.  like a down rail, c box, trap box, etc etc.  for jumps, keep them nicely shaped and keep the landings not to icy.  make like a 15 footer, then like a 25, 40, etc