A renter can get get roommates or landlords can subdivide properties further. Renters may also consider increasing their commute time.
2bdrm to 1brm, 1bdrm to studio, studio to van.
van to nap-pod
Compromise on neighbourhood. If you're in SF instead of living in the nice areas, go to Tenderloin, Hunter's Point, etc. You can find great deals in those areas.