KEEP YOUR GRADES UP!
Strive for a high GPA in the classroom, and study hard for the SATs and ACTs. The higher your grades/scores, the more schools will recruit you, the more options you'll have, the less stress you'll feel.
EXPLORE ALL LEVELS OF OPTIONS.
Don't be afraid to explore your options at every level: DI, DII and DIII. Evaluate yourself honestly on your abilities and your commitment level in college, it will help steer you toward the right level of play. But don't rule out any level without educating yourself about the school.
DON'T LET LACROSSE BE YOUR ONLY FACTOR IN PICKING A SCHOOL.
Choose a college or university that is a good fit for you academically, make sure it has your major, that you like the environment, size, etc., and that it fits your interests, and you will be a happy, willing participant in your sport and your college community.
BE PROACTIVE IN THE RECRUITING PROCESS.
Just like anything else, the harder you work, the better your results will be. One of the most difficult things about the recruiting process is that most athletes must sell themselves. To be recruited, you have to put yourself on a coach's radar and continue to be proactive to help yourself throughout the process. Email or write to the coaches of the schools you're interested in, explore any camps and/or clinics they may be attending, and keep yourself in the forefront of their mind.