The amount of fabric you buy will depend on the size cushion you are making. Measure your cushion insert (or decide on a size of insert if you do not have one already). You will need 2 1/2 times the length of the cushion insert, as the fabric will be covering both sides of the cushion with a little overlap. Your fabric should also be a few inches wider than the width of the cushion insert, as you will need a bit extra for seam allowance. [1] X Research source
If your insert is very fluffy you may need to add a few more inches to the width. If you are unsure of what width you should cut, put your insert on top of the fabric. Make sure the width of the fabric will fit up to the center of the sides of the insert plus a few inches for seam allowance. Your piece of fabric should end up being shaped like a long rectangle, with two long edges and two short edges.
Repeat this on the other short end of your fabric.
Once you hold the fabric you should have the wrong side facing out. Pin along these two edges, through both layers, and sew along the seam.
Iron your cushion cover before putting in the cushion if it has become wrinkled.
Discard the arms and neck area you cut off. The piece of the t-shirt you keep will be shaped like a rectangle.
If you prefer, you can stuff your t-shirt cushion cover with cotton wool, wool, or thin sheets of cotton, instead of a pre-made cushion.
Pin the bottom edge of the front and back of the t-shirt together. This will form the bottom seam of the cushion cover.
You can use your sewing machine to sew the seam as close to the bottom edge as possible, but it could make a slightly awkward edge if you are not experienced at sewing.
Another decoration idea for the more patient or experienced sewer is to embroider a small picture onto the front. This will make a nice centerpiece on your cushion cover.
