I tutor folks (whose parents [usually] are the' expense account') in English (literature), Reading and Creative Writing. The students most often need a lesson in 'time management' first. I've edited several newspapers in the past, all for pay.
I edit and revise people's work at the Writing Commons. Usually it's student work, but sometimes it's grad students with Master's Theses or Doctoral Dissertations, and once I've even worked with a professor.
Even though I want to someday be part of a big publishing company, I'm not against trying my hand as a freelance editor for self-pub writers or bloggers. I technically have freelanced once before; I proofread and edited a children's book a friend wrote, and got $25 and a starbucks latte out of it.
The key for editing seems to be, if you're unsure about something (APA style, or comma rules) have resources available to help you. Chances are you're using the internet, so there's a lot you can look up.
That's very cool that you're trusted with larger work.
I've been thinking about having freelancing as a backup in case I can't get a full-time job right out of school, which is why I posted this poll. I was just interested in seeing the way other people have gone about it and what their experience has been like.