I have summer ones that I made with faux gingham and stitched bugs on them,
I wanted something to go with the placemats that I use when we are dining outdoors on the deck. I fashioned these spring-themed napkins that work with the placemats.
The napkins are easy, peasy to make. I buy a yard of fabric (a metre if I'm buying fabric in Canada) and cut into quarters. I stack and trim them to the same dimensions.
Then I iron a 1" hem all around and tuck the raw edge up to the ironed edge and top-stitch all the way around, mitreing the corners. There are lots of helpful videos/websites with instructions for mitred corners.
And that's it! Do your bit for the environment and use cloth napkins!