Scholarships. Apply for as many as you can, they add up. In high school the AVID kids were racking up the money, most with 30-40k+ in scholarships, a couple with enough to cover it all. I made the classic mistake of not wanting to put the work in and write some essays so I had to pay out of pocket.
Also don't be foolish and go to an out of state school because you'll get reamed on tuition. Most curriculums don't differ that much so just get the piece of paper and move on.