On the back of one placemat draw out the stocking shape you want, trying to get as much stocking as you can from the material. Then trace around that shape again giving yourself anywhere from 1/4 to 1/2 an inch for a seam allowance. (I try to get 1/2 inch because I'm not very good with a sewing machine). I also make the top 2 inches of my stocking a bit wider so as to give enough room for a folded cuff.
Now use that first stocking cutout as a template for the rest of your placemats. Now comes the only tricky part to this. In order to make the top cuff of your stocking (and you don't have to have a cuff if you don't want to, or you could even add your own fancy cuff if you are so talented, but I'm not) you need to:
1: Put two stocking shapes together with the right sides facing (make it look inside out). Then, starting 3 inches, or so, from the top, sew around the edge of your stocking and stop 3 inches, or so, from the top on the other side.
2: Turn stocking right side out. Now, sew up both sides of the stocking top. Does that make sense?
See, here I've sewn most of the stocking, turned it rightside out, and am finishing up the top.
See? On the green one I made the mistake of only sewing the cuff part inside out. With the cream one I was smarter and added an extra inch to that insideout seam.
The reason for adding that extra inch is so that the raw edges on the inside aren't so near the top (which makes them visible and sloppy looking). See?
And here they are, all finished. Now I will use a stencil and some gold craft paint to personalize each one. Another reason I like using placemats is that most of them have some sort of interfacing inside them which makes them rather sturdy. I didn't add any loops to hang them from because we rarely have a fireplace and usually just prop them up on the couch, but I'm sure you could easily add a loop before sewing it together.