Tuning pegs.
I once had a friend who played a beautiful flamenco guitar that was built into his arms. The tuning pegs were "real" tuning pegs in that they were handmade pieces of wood fit into beveled peg holes. To tune the cat gut strings he'd pull the peg out a little bit and twist according to the needed adjustment and then push the peg back in the hole. Then when everything was tuned perfectly he'd play like a demon possessed. And. of course his girlfriend was a belly dancer. Made me realize that you've always got to customize what's yours to bring it closer to the heart.