I love satin pillowcases. They're so soft and much easier on your hair than any other fabric. These instructions will get you two standard size cases. My family is requesting these all the time. They make a good easy Christmas gift and they take no time to make.
Fold a one yard section of fabric with right (shiny) sides together - double thickness. Find an existing pillowcase. Place the pillowcase on top of the folded satin.
Trace around the perimeter of the existing pillowcase with the chalk allowing for an extra 1/2 inch on the bottom and sides. Allow for an extra four inches on the top. It doesn't have to be perfect, just get it as close as you can. Repeat this step with the other yard of fabric.
Cut out satin following the lines you drew. When done, you should have two separate pieces of satin. Do not separate them!
With right sides still together, using 1/2" seam allowance stitch straight down one of the longest sides all the way down. Cut threads and reposition to stitch across the bottom all the way across. Cut threads and reposition coming all the way up the other longest side. Your stitches will have crossed each other at the bottom. Cut the two bottom corners at a diagonal. Be sure not to cut through stitching!
Grab the top unsown edge and fold it back 3 1/2 inches and pin along the folded top edge. The shiny side should be facing you 3 1/2 inches all the way around the top.
Now take the raw edge and fold back under about 1/2 inch. This will keep the raw unsown edge from fraying. Pin and stitch all the way around.
Flip the case right side out. You are done unless you want to add another decorative touch. If so, see step 8.
See the stitching near the top where you performed Step 6. You can cover that up by pinching enough of the case up and over that stitch. Pin and sew. This creates a little decorative ruffle toward the opening as seen in my photo.
Now repeat all steps to make your second satin pillowcase!