I made this because I was tired of carting around my size-of-a-small-house laptop bag. It's huge. Gargantuan. Yetch. Anyway, so I made a little sleeve!
WARNING!!! There is hand sewing involved. I busted two needles on my little Singer by being foolish...yeah...AHEM. Anyway, don't do what I did.
Cut your fabric...I used my laptop to measure. You use yours.
Round the corners on one end of your fabric. This is going to the be end that becomes the flap on your case.
Sew your velcro on. Remember: you want to sew one piece to the bottom (non-curved) end of your exterior fabric, and one piece to the top (the curved end) of the interior fabric so they will line up when you fold it like a case.
Sew the fabric (wrong side out) together around the edges. The fabric that you want on the inside (the liner) should be in the middle, with the right side against the right side of your exterior fabric. Leave a hole (a few inches) along the one side.
Turn it right side out through the hole in the side.
Make sure your velcro still lines up...if everything is in order, sew up the hole in the side
This is where the hand sewing comes in: fold your bag as though it were inside out. I quadrupled up on the thread, because it is so thick and you're going to want it to be sturdy. Sew up both sides.
Turn it right side out...PRESTO CHANGO! There is a laptop case! Make sure your lappy fits and have lots of lappy fun with your new case!