I love homemade costumes. They're the best. Costumes that require minimal purchases? Those are great too. This year's costume required a piece of foam board, craft paper, yellow poster board, and a brown marker.
French toast! (Accompanied by that one ultra annoying backpacker at your hostel).
If I'm counting correctly this was my third food costume. The first was a candy bar in childhood and an ice cream cone the year before last.