How to get some easy cash?

im a college student living in my apartment with bestfriend. i had a lot of money saved up but i wasted alot of it in the summer and now i need to start saving again (my bank account is dangerously low) but its hard with rent, school and car etc. i have a job while in school. i started giving plasma to help some of my expenses. does anyone know any other easy ways to get money besides selling my possesions and getting another job? i doubt it but maybe someone else knows of something.