Do your best in class. Keep in mind that this is an academic program to which you're applying. If you're struggling academically, consider resources such as advising, counseling, and tutoring if you need extra support.
Develop good relationships with professors. This will help you later on when you need to provide letters of recommendations, and advice, for law school.
Get involved. Law Schools take a quality-over-quantity approach when considering your extracurricular commitments. Select genuine activities of interest where you can make a substantial contribution, rather than several activities in which you are superficially involved. Admissions officers like to see evidence of leadership, initiative, communication skills, and commitment.
Be an informed consumer. It is essential that you are thorough and exhaustive as you research different law schools and use a variety of sources, visit individual law school websites, attend admissions information sessions on campus, speak with current law students and alums about their experiences. Most of all, know yourself and what you are seeking out of this experience.
Be self-aware. The most important thing is that you know who you are and are making decisions that are authentic and to you. Note what kinds of activities energize you, what kind of environment is stimulating and do the research to learn where you will be a best fit.
See the long game. Admission into law school, while exciting, is not the goal; a long successful career is. The skills you learn at law school, or any graduate school, are tools to help you in your success. Don’t ignore the importance of experiential skills and professionalism along this long journey.