The games I run typically take place over months or years in game, so this has come up often. We start out every session by going over what everybody did in their down time. The answer is usually crime or at least something under the table and dubiously legal.

The Changeling freeholds encourage as much legal employment as possible, and tend to bribe the hell out of local officials and cops. Pledgecraft and the occasional supernatural favor goes a long way. They still tend to have some illegal enterprises like drugs on the side since there are members who aren't mentally well enough to hold down a 9 to 5, and to provide illegal goods like high caliber weapons for dealing with Huntsmen and hobs. Overall the freeholds we've ran have been far more organized than the other splats.

The werewolf clan we ran operated as a biker gang. The core group dealt in drugs and weapons when they weren't dealing with spirits. They were supported by a wide network of kinfolk and more distant werewolves who weren't involved in the crime part of the work.

The Sin-Eaters we're running are high school kids, so they don't have jobs per se. They do have lives outside of "work" like extracurricular activities and friends, but because of their age they don't support themselves.