Hey chad, I think I got it. Last night I twisted up a 12 strand B500. I took a clip that holds a bunch of paper together and help the top loop where I quit twisting 6" from the last tag end. I then did the bottom loop and after twisting up 4-5" after the last tag end, I cliped that off. I then twisted the entire string several times and took the clips off and it seemed great.

And afterwards my hands killed me.

Its not great, but if I am going to continue to build bows, I need various length strings in a hurry with various length loops.