Best thing you can do is score 34+ ACT / 1450+ SAT and get As in the most challenging coursework available at your high school. I think the largest OOS scholarship + the UASP scholarship total is just shy of full tuition. They will want to see some good extracurriculars and service - but I think key factors are test scores, GPA and coursework… and the higher those are, the more money they are likely to award.