As long as you have a sewing machine, they are simple, inexpensive and take almost no time to make.
Instructions are below the photo.
For lots of great sewing ideas, tips and instructions, click here to visit Mary's site. I have tons of them at home that I've made, that way you never run out. The napkins in the picture are 17 inches square. Cut out your squares and serge the edges or turn raw edges under and sew a line of straight stitching. Use your imagination and see what you come up with.