Another best side hustle for students in college is becoming a tutor

Agreed! I was tutoring as well to supplement my pocket money. It's easy entrance, takes about 2-3 hours of your time and you also learn how to manage others. More students should try tutoring since not only it'll help fill your pocket but also helps with learning some important life soft-skills.

Another tip I'd add is networking. Sometimes your network knows a thing/two about job opening or opportunities. And the last would be investing, these days, investing is easy and has low barrier, you can invest as little as 1$ these days. That's what I did before; investing my day job money to cryptocurrencies before I became 80% on it.