Lots of good advice here already.  I agree especially on these points:
- On steep faces, really shorten your uphill leg as you come around.  Pull it up and let the hill push it up.  You'll come around quick, easy and much more stable.
- Run blue groomers top to bottom switch, outside the park.  Including the steeper top faces.  It's grueling at first, but it forces you to deal with all terrain rather than just on the easy parts.  Plus you get tons of turns in and normal people will think you're awesome.
- Spend a couple whole days skiing switch on all the groomed blues.  Every run, top to bottom.  All day without going forward except into the lift line or when you get into tight crowds... to keep ski patrol happy.
- Learn to use your edges.  Switch skiers often look like they're riding flat, but the good ones are grabbing the snow with their edges while curving.
- Apply early pressure to the outside ski to initiate turns.  Give it a real push.  This will bring you around quicker and engage your edges.