Less caffeine, less stress, and more relaxation. Otherwise, go to your local sporting goods store and pick-up a mouth guard (the kind that you boil in water to conform to your teeth).

get rid of the stress in your life.
once it's gone, the grinding will stop... worked for me!

Getting a custom made mouthgaurd through a dentist is a remedy. I'm a jaw clencher and that's what I need also..but yet to get it.. oops!

Get some kind of mouth guard before it's too late, then maybe try some of the stress-lessening the first commenter mentions...

My dentist has been recommending one of those for years but i was put off by the cost (about $300). Last time I went, they said i have almost no enamel left on some of my teeth (and i'm only 30). That will never come back, of course. There are over-the-counter mouthguards (I believe there are OTC ones specifically for this problem, as opposed to sports-related). I asked the dentist, and she said, if it works, great, but will it stay in and will it be comfortable enough that you won't mind wearing it? Worth trying, I suppose, but i decided to (NOT bite the bullet) go ahead and make an appointment to be fitted for the real deal.

Also, another thing she recommended (not to stop grinding but to protect teeth a little) is to use sensitive toothpaste, because the way that stuff works is it builds up a layer of mineralized flouride on your teeth, which protects the enamel a little (it takes a while, so give it time). Apparently you can disregard the "don't use more than 4 weeks" warnings on the stuff, because that's just in case you are using it for pain that a dentist should look at.