The surprising thing that has helped me sleep better and have less headaches.
I have been a jaw-clencher for as long as I can remember. When I'm working, driving, or focusing, I naturally clench my jaw. Somewhere along the line, that turned into doing it while sleeping and occasionally grinding my teeth. When my dentist pointed out that my teeth were really getting worn down (she wasn't kidding- I could see significant tooth flattening in the x-rays), she persuaded me to wear a mouth guard at night.
The mouth guard she offered me was hundreds of dollars, so I passed and did some research. I found this option on Amazon and have worn it every night for the past four months. Not only do my teeth look the same as they did four months ago (no more flattening!), but I have had significantly less headaches on a weekly basis. I have always struggled with frequent headaches, which I chalk up to genetics, hormones, stress, and Mercury being in retrograde most of the time. I hadn't realized just how many of my headaches were actually probably tension-caused from my nightly grinding and clenching sessions.
This mouthguard has seriously helped my teeth, stress level, and sleep quality. $23 bucks well-spent!