I've been doing audio mastering as a creative hobby for about 5 years but I've never done anything professionally. I was literally just contacted early this morning (EST) regarding an opportunity to do some work professionally for an indie record label so I am going to see where that goes. There is a "Full-Time Effort" clause in my employment contract that might require me to get permission from my company to do it, but I'm hoping it won't be an issue either way.