Measure the pillow case covers and cut 4 pieces of the memory foam the same size using a yardstick and marking your cut lines with a Sharpie pen so you have the right size and cut a straight line (I used scissors to cut them). One at a time, tuck two of the pieces carefully into each pillow case so there are no lumpy spots, and zipper them in. Cover as normal with pillow cases. They are very comfortable and affordable.
Afterward, I took two small strips of leftover foam and inserted them lengthwise into an older pillow case and tucked the ends of the pillow case in. I use it as a lumbar support for my back in my car. It gives just the right amount of support and it isn't lumpy because it molds to your back.
You can make pet beds using this method also. Much cheaper than buying them from the pet store.
By ann from Goulais River, Ontario