My fitted sheet keeps slipping off the corners. How can I fix this?

Make sure that when you shop for fitted sheets that you purchase the ones with “deep pockets,” and if possible, buy ones with elastic around the entire sheet edge. I know it is hard to tell when they are in the package, but from my experience the more expensive sheets are made this way. For older sheets here is a solution – https://www.amazon.com/dp/B004I3VDWY