Your favourite/most unusual money-making methods

Even if my gameplay is centered around supernatural Sims, I love playing the Rags to Riches challenge from time to time. I forbid myself to make money from frogs, rocks or gardening because you can't do that in real life and I like to keep it realistic. I make my Sim a kleptomaniac and she/he has to survive with stealing things only, I found it really funny and realistic actually.