When I was a young teen, I made my own that was basically just a strip of fabric with a zipper connecting it into a tube shape. It worked for years, thankfully I got an underworks one later on. I hated that binder though, it was so thick and hot and uncomfortable, I have a small chest and it had a LOT more binding power than I needed.
I used duct tape to just pull my breasts to the side at a party one night so I could be shirtless haha, I was among friends and it was all good, I only had it on for a few hours. Hurts like a bitch to remove, I can't imagine how bad it would be to wear all day D;
I can't think of anything else really. I've had a proper binder since high school and haven't needed to use anything other than that.