I know it's anti-mustachian, but we own a small summer home which we only use for a month. (Maine Coast) This year, we rented it out through air BNB for August, when we're back home (Crested Butte), and rented out our full-time home for July, when we were in the summer house. Between that, and having air BNB guests in our guest room when we ARE at home, we cleared 10k this summer. Yes, we're crazy lucky to have these options, but it's well worth thinking about making some of the choices about where you live be dependent on how well you can rent the spare room, or the whole place, to help pay for it.