*1 yard of fabric (you will have leftovers, but let's play it safe)
Lay your fabric flat with right sides facing in. Measure the length you will need with an existing pillowcase. Make sure to leave 1 inch extra fabric on the bottom seam and one side seam. Leave 5 inches on the other side.
Pin together and sew together one side and the long bottom. Make sure you surge or zig zag after to reinforce the stitch.
On the length wise stitch, stop your stitch about 5 inches from the top. Turn the pillowcase right side out and sew together the remaining 5 inches.
Keeping the pillowcase right side out, fold and press a hem about 1 inch.
Then fold and press again so now your hem is 1/2 inch (making sure you are tucking the fabric under.)
Decide how big you want your casing piece and fold over. Press flat and Pin (I did mine to be about 4 inches)
Sew 2 Straight seams as close to the edge of the fabric as possible.
Good work! Now go take a nap! :)