I pretty much look for anything at all that looks out of the ordinary in the engine compartment (no matter what's explicitly stated in the checklist) as that is what I've been taught. Checklists just give you the bare essentials, in my opinion, and after all they are check lists, not do-lists! AFE checklist is preferred at the school I'm training at, but I suspect that I'll develop my own at some point in the furure.