What weird adjustments have you made to your sourdough?

Hey everyone! I've been baking sourdough for about a half-decade at this point and feel like I've got the basics down. What do you guys do when you want to do something weird with your sourdough? I've heard of adding fruit to a starter, but I don't think that would work because the sugars won't be as freely available for the yeast as in a liquid.