Just like you said, don't throw gears on it for no reason. I would leave them off the vest at least. Maybe a tie pin that's a gear, but I wouldn't just put them on.
As a composer, I would think maybe you could carry a conductor's baton but steampunk it, maybe have some glasses that have all the different magnifying lenses like they are wearing them while they write, maybe some steampunked quills for writing, scrolls of parchment in a satchel, things like that. I would accent the costume with musical details more than gears. Maybe you can carry some sort of instrument and steampunk it.
Those are some quick thoughts I have for a composer at least.