We found these on CTA Glam Couture’s website, along with some others. They’ve got some cool stuff at their shop too. Apparently the graphics are from the book 99 Ways to Cut Sew, Trim & Tie Your T-Shirt into Something Special, which is less than $15 and probably worth picking up.
We cut up clothes all the time at Too Fast. It’s just part of designing and trying different art on different styles. If you’re into DIY or fashion design, it’s something you’ll be doing a lot.
It can be expensive if you mess up though, and it might take a couple tries to get it right. So we recommend getting some thrift clothes or blanks from a craft store to practice first.