I use a nose clip (sometimes called a nasal dilator) that has improved my sleep quality tremendously. I used to wake up feeling dizzy and cotton headed. I usually couldn't cognitively function until mid-afternoon and felt like I had a sinus infection every morning. It's made a huge difference. I wake up clear headed, my wife says I don't snore as badly, and I've started remembering my dreams again suggesting I'm getting quality REM sleep again.