I've been having real good luck with squirrel and calftail on clousers down to size 14. I've also been playing with fox, coyote, and, on very small clousers, rabbit. I've seen some cool looking ones done with craft fur but haven't done any myself. I've found Super Hair to be a little difficult to tie in securely on smaller clousers without creating way too much bulk at the eye of the hook.