Sew a 3/8″ seam all the way around the square, leaving an opening about 4″ wide for turning right-side out. After sewing clip the corners off (but don’t clip the stitching.)
Another quick method creates 5 hot pads at once (or more, depending on the size of the pieces of fabric you use.) In this case I used 2 coordinating 1/4 yard pieces and a piece of batting that was 43″ x 9″.
Press both pieces of fabric and the batting before you start. Take the backing piece and lay it face down on a clean surface. Spray lightly with Basting Spray (available at most sewing supply stores). You may want to do this outside to prevent sticky spots in your house.
Trim the batting so that it is slightly smaller than the backing fabric and lay it carefully on top of the backing, smoothing out wrinkles.
Then I carefully quilted some parallel lines to hold all the layers together nicely. The stripes on this fabric worked great as a guide, but you could mark lines with a disappearing marking pen or just eyeball the quilting lines. Basically it’s nice if you have a few lines at least 2″ apart – but you could do more if you like. Or this is a great chance to practice your free-motion quilting skills.
(I bought this Cosmo Cricket “Early Bird” fabric last year.)
When fabrics and batting are nicely quilted use a rotary cutter and ruler to cut out the hot pads. I cut five 8 1/2″ square hot pads out of a 1/4 of a yard of fabric.