If you are single and flexible, house-sitting could be a good option. I work in a high COL city (room are $850+, apartments are $1500+, houses/mobiles are $2000+) and even with a 6-figure salary, I can't wrap my head around having to fork so much for a place to sleep, so I took up house-sitting a few weeks after I moved here. When I got here, I spent a few weeks as an office hobo but I was lucky to find very quickly a permanent house-sitting gig for someone who works on 2-week rotation at a mine. When she is back, she is happy to have me stay at her house, but I like my privacy, so I become the office hobo again, which I really enjoy for a number of reasons. Since I took this job a year and a half ago, I have not paid a cent in rent.
Living in a car/van is another good option, weather permitting. I plan to do that at least for a year after I RE in October 2016.