A bed wedge is an angled pillow that tilts the neck and head upward to reduce the complications of sleep apnea and other sleeping problems. A wedge can range from 8 to 12 inches high at its highest part and the angle of the wedge can vary depending on what you like. Wedges can also be made of different types of foam and range from soft to hard. This type of pillow is not hard to make.
Visit a foam store (or upholstery shop) and have someone cut a piece of foam into a wedge shape for you. Pillow width can range from 24, 30 or 36 inches. Select the width that matches your bed pillows. Start with a foam block that is 8 to 12 inches thick.
Specify the height of your foam block based on the amount of incline you want. Ask the salesperson to cut the foam on the diagonal so that the thick portion will be the top edge of the pillow and the thin portion the bottom. One foam block will make two pillow wedges. It's better to have your diagonal cut with the store's specialty wire or cutters for perfect shaping.
Round the edges of the pillow and corners using an electric carving knife. This will soften the corners.
Purchase a sheet with a high thread count. Wash the sheet. Fold the sheet and place the sheet on the work table and position the wedge on top of the fabric. Cut around the pillow adding a 1/2-inch seam allowance on all sides. Position the wedge on the triangular end and cut around the shape adding a 1/2-inch seam allowance. Position the wedge on the flat back surface and cut around the shape adding a 1/2-inch seam allowance.
Pin the top, bottom, and two triangular wedges together with the seam allowance, face sides to the inside. Sew the seams.
Fold the two rectangular pieces in half along their long edges. Pin a zipper to the back side of the folded pieces so that the folds touch and center on the zipper. Sew the zipper to the fabric. Place the cover over the cushion with right sides toward the cushion and pin the zipper end to the seams of the other pieces. The zipper should be facing the cushion. Leave the zipper open a few inches while you pin.
Slide the zipper open with your fingers and remove the cover from the cushion. Sew the seams. Turn the cover right side out and place it on the cushion.