I had to take a gym class and a needed a tote bag to carry a change of clothes, water bottle, and my essentials (phone, wallet, keys). Instead of buying one, I took an old Batman hoodie I had and made it into a tote bag.
I found this awesome homespun yellow plaid fabric at Joann Fabrics for the inside lining that matched perfectly. I took apart the hoodie with a seam ripper and drew my pattern right onto it. Since sweatshirt fabric stretches, I attached a stiff interfacing to it. I used left over pieces of the hoodie to make pockets on the lining and added a welt pocket.