Pillow covers are a simple, low-commitment way to change up the look of a room. We've made this style of cover for our throw pillows for years. They slip on and off through an overlapped opening in the back, they look clean and simple, and they're a cinch to make:

What You Need

Materials
pillow
fabric

Equipment [OR] Tools
sewing machine
scissors
measuring tape or ruler

Instructions

1. Measure and cut a rectangle from your fabric according to the pillow size. Size the rectangle with the following formulas:
L = (pillow size x 2) + 4"
W = pillow size + 2"

So, our rectangle for this 12x12 example pillow is 28 x 14.

2. Hem the two short ends of the rectangle.

3. Fold one short end toward the center of the rectangle, with the "finished side" of the hem facing down. The length of the fold should follow this formula:
X = (pillow size / 2) + 2"
So, for our example, this folded portion is 8" long.

4. Fold the opposite short end toward the center. The length of this folded portion should also be 8". This will create roughly a square, with two folded sides and two open sides. The hemmed edges of the fabric will overlap by 2" at the center of the square..

5. Sew shut the two open sides of the square.

6. Turn the cover right-side-out through the overlap at the center.

7. Insert the pillow through that same overlap.

8. You'll want to iron the cover once it's complete - a step we obviously didn't do in this example! This will flatten the hemmed edges and smooth the seams, making the results look more finished.