Great business ideas for 13 year olds

Let's collect great business ideas for our sons and gals. -low risk -no upfront money is necessary -easy to do on afternoons I start: When I was 12, I started a valentine's roses business in my school. It went like this: - at the beginning of February, I sold cards for $5 each -fellow students could write a note on them, and the addressee -I then collected the cards -on the 14th, we gave out the cards along with roses and brought them to each class The advantage for my customers: they could often stay secret but still let their love be known. My advantage: I knew exactly how many roses to order and knew my profit before Now let's hear yours!