Used to.
Get one of those $0.99 boil-and-bite mouth guards from the local sports store and trim it down so it's unnoticeable/unobtrusive to your likings (their a bitch to sleep with at first, I always felt close to gagging a lot until I took most of the plastic off the part that touches my pallet). IMO you just need enough to keep the upper and lower molars separated a little bit, you’re back molars don’t need full coverage if the ones in front of them a being seperated.
Then, if you chew the shit out of that thing, go see a dentist and get fitted for a custom one.
For some reason, I stopped grinding on my own. However now I find myself waking up with my fists balled and my arms dead asleep – so I don’t know WTF is up with that. But anyway, go and try the cheap option first and give yourself a few nights to get used to it.