I had a really old black swimsuit that I loved, and the shape was fabbo! But it was worn out and there were holes and faded patches all over the front of it. Not good for swimming in! I took another old swimsuit that I didn't really wear (but I have seen loads of old swimming wear in charity shops - as long as you don't reuse the bottom region, you're pretty safe reusing the material) and paired them together!
You can check out how I made this here.