Earn a raise. Cutting expenses is quicker than any source of extra income so look there first. Write down everything you spend a year then find what you can cut, everything must be on the cutting block so decide what hurts least. When I was 18 I rented a single room and ate very little, walked every where, no phone or tv or car or anything extra not even a radio. If you have extras like phone, internet, cable tv, car, etc decide which you are willing to not keep, the car is the most expensive with insurance and maint cost. Keeping the car might mean a second or third job earning a few hundred a month.
Work.
work for it
give blood