Do not ever, ever dress up in a costume or act out a role in a presentation. Putting on costumes will make you look ridiculous. Acting out a commercial will make you look like a band of idiots. I worked on a pitch for a razor brand where the creative team popped out of a closet in bath robes, then made the presentation as if they were fresh from their morning shave. It went over like the Hindenburg on wheels. Do not dress up. Ever.