I always get way too caught up on what I actually want out of a mid to low poly model to actually finish texturing and rigging one.

Usually I get hung up over trying to do something like achieve HL2 level facial flexes with half the triangle count. Or I get caught up over whether I want realistic anatomy or anime style anatomy or if I want both to use the same base mesh, or what kind of texturing method or maps to use. So a lot of my stuff has been gathering dust for years as a result.