Fake product and TV commercial ideas?

This isn't homework for school but I need help. I'm going to an acting/modeling workshop tomorrow for a cruise this summer to audition for agents and stuff and I just found out I need to write a 10-15 sec commercial for a fake product. No props allowed. I have to perform the commercial in a competition they automatically put us in. I have no idea! I've read them but never wrote a commercial before so I could really use some ideas and slogans and stuff. Thanks:)