I made this pencil case a while go in the school holidays. I can't really remember how I made it but I used 3 fat quarters with different coordinating fabric patterns.
I added a large pocket for my bulky calculator, ruler and notes, etc. This lets my pencil case take on some shape as well, so it's not just floppy.
It keeps all my stuff well organized. I don't have to rummage through deep, dark and cavernous pencil cases to find my favourite pen.