Autogenics is a biofeedback technique that induces a state of intense relaxation. It's supposed to be able to help change compulsive behaviors, though I haven't tried that myself. I have found it very helpful for getting to sleep, though, and pleasant as well. I used this guide for what I have done so far.

Fun anecdote: Once, while I was cuddling with my boyfriend, he said, "I can hear your heartbeat!" A few moments later he jerked and looked at me in shock. "It just slowed down!" :-) I felt like a wizard. Biofeedback is cool.

It's probably worth trying if you have problems sleeping. Interestingly, it's found to be useful in treating a several mild mental and physical problems, like headaches, anxiety, mild depression, and sleep disorders. It's also used for pain relief for natural childbirth. (Meaning, for women who don't want to have an epidural.)