Check out these super magenta cloth napkins I made for Elaine:
They're made from quilting cotton, of course. They finish at 14.5" square.
These were really easy to make. Pin two layers of fabric right sides together, sew around the edge leaving an opening on one side (about 3"), turn, poke the corners into submission with a knitting needle, iron and topstitch around the edges.
And you're done! I'm making some with white on one side which I like for its simplicity but I also like the punch these double sided pink napkins have. They're twice as fun, you know?
Also, here are a few of my favorite cloth napkin tutorials:
Napkins with binding around the edges.
These are like mine but with running stitch embroidery.
This tutorial is for embroidered handkerchiefs but it would definitely work for napkins too.