Flexible Job / Freelancer for full income?

So I want to study and work to support myself since I need to earn a living. Up until now studying works besides my full-time job, but I’d like more independency, so I wanted to become a flight attendant with more free time, but since that didn’t work out either I need a new idea.

I already did freelance writing and translation work on eLance.com and I need tips on how to earn a full income with a flexible job other than flight attendant or as a freelancer.