a sewing machine
a piece of fabric
a ruler (if you're wanting to gather it to a certain size)
You can do this on any sewing machine because all you need is a straight stitch! I am using my slightly terrible Brother than I have worked nearly to death. You will notice the tension is not quite right in the photos.
At the beginning of this year it decided it didn't want to do much of anything right, especially when it involves sewing through a single sheet of fabric. ;)