I love love love picking and tearing at the skin above my nails. I don't bite my nails, but I attack all that rough skin there.

I also want to stop! The best thing that's worked for me is a thick cuticle balm. Burt's Bees, or Badger Balm both make a product like this. I keep it with me especially for occasions when I'm prone to picking: during a movie, while reading, studying, long car trips.
The act of rubbing balm into each fingertip fulfills the compulsion to do something with my hands. And when you're done the skin is soft & impossible to tear at! Also it does not taste good. Try it!

Link: http://www.amazon.com/Burts-Bees-Cuticle-Creme-Butter/dp/B00013YYS0

It's not an oil, but I love Burts Bees cuticle cream. I got the Essie sample too and was honestly disappointed. I just like the smell of lemon better, I think. And you can even get a pack of 3 Burts Bees for $11 now.