I don’t know if you remember this post; ya know, the one where I made an attempt at a Kindle Case. Well, I finally made one that works for my Kindle 3. I am very pleased with the outcome.
Instead of doing the buttonholes for the magnetic snap, I just used fray check, like in this tutorial by Keyka Lou. I made the measurements 20 x 6.5 with a 3/8 seam allowance on all sides and it fits perfectly.
I learned that you have to iron more than you think is necessary when top stitching. It will help to keep everything in place. You will also always see part of the inside fabric.