1. The tennis ball trick
Do you sleep on your back? Try the “tennis ball trick”: sleep with a tennis ball (or similar sized ball) attached to the back of your pajama top. (You can sew or safety-pin a sock to the back of the pajama top, then put a tennis ball in it.) The tennis ball is uncomfortable if you lie on your back, and you will respond by turning on your side. Soon you will develop side-sleeping as a habit and not need the tennis ball.
(from How to stop snoring by Helpguide.org
Speak Your Mind