Click on "read more" to get the full how to.
I think I could have made this fancier, maybe added a border and what not, but I really wanted to make it during his nap, so this is quick and dirty. And easy.
You need a yard of each material, pins, thread, and your sewing machine.
Place the wrong sides together, and pin all of the edges. Make sure that you aren't getting wrinkles in the fabric as you pin more sides.
My fabric was not cut square, so to cut the corners at right angles, I laid it on the tile floor of my kitchen and used the grout lines. I'd like a nice cutting guide, but I don't have one, so the tile will have to do :) Also, the grout lines make a nice channel for the scissors.
Leave an opening on one side of your fabric. Mine is about 3 inches long. I marked where I wanted to start and stop the opening with pins so that I wouldn't accidentally stitch it closed and have to get out the dreaded seam ripper.
Sew up all sides. I used a 1/4 inch seam allowance. Backstitch on each side of the opening. For corners, leave the foot down and turn fabric 90 degrees. When done, cut the corners out so that they are easier to turn right side out.
Pull blanket through the opening that you left. Poke out the corners.
Top stitch (sew on the right side of the fabric. This makes it look finished and also closes up the opening you left in the first seam.) all edges. I used a 1/2 inch seam allowance for that. When you get to a corner, leave the needle in, foot down, and rotate the fabric 90 degrees.