Take it seriously. Yes, you’re applying for an online job. Yes, you can do the work in your underwear, but that doesn’t mean it’s not a “real job”. You must treat it as such or they aren’t going to treat you as a serious candidate. You aren’t the only one who wants to work in their underwear. In fact, the competition online is likely higher than it is in your local area.
Websites like Care.com connect parents with babysitters. The company does all the background checking and other due diligence to put parents' minds at ease. Of course, you can appeal directly to people in your personal network, but if you're looking to generate recurring revenue sign up with a site marketing to parents looking for child care services.
Set up a roadside stand. Depending on where you live, you could profit handsomely by setting up a roadside stand. If you live near a resort area, for example, you could buy cases of bottled water, put them on ice, and sell them to passers by for twice what you paid. Selling fruit and produce you grow yourself is also a smart idea in highly-traveled areas.