Street shooting models. Now most cosplay don't go back to find professional secondary models, but choose cheaper part-time college students, and female college students with all kinds of looks and roles have everything.
Distribute leaflets. I believe many college students have done it. Students in our class used to do it occasionally on weekends. This kind of work is generally immediate and unsustainable. Generally, you can get a certain income in an hour or two. It's good to go out for dinner or buy some good cosmetics.