I have made a rough copy out of paper to give you the general idea, it is very simple and you can make the size to fit your scissors. I have taken a few pictures to show you hold to fold it. You make it out of three layers just like a mini quilt, it can be plain or pieced or crazy patch looks good, two coordinating fabrics are best as they show side by side in places!!
Now we fold the left hand side over to the first fold
This is basically a rectangle shape with the top left corner rounded off
This shows the right hand side folded over diagonally to the point (bottom right)