Freelancing is a good option, unfortunately I don’t have a lot of experience on it, so I don’t know how easy or stable it is.
Big games, that have bigger budgets, usually have full-time people working on them, as it makes things easy. From my experience I’ve seen freelancers being hired for smaller projects only.
I’m doing indie work myself, working full time for a company. The best advice I could give to succeed as an indie, is keep making games, and do your games to make sure your newest project is better than your previous one. When I say “Better”, I don’t mean financially, or amount of downloads. “Better” can be, using new technologies, or experimenting with a new idea.
The first step to take as an indie, is to finish and publish a game, regardless how good it is. The second step is to make a better game.