Internships. That's advice more for the currently enrolled but I regret not taking more advantage of it. A stellar intern is often ushered into a job whereas another individual with the same resume but lacking in the "known quantity" factor would be left out in the cold. Even if no job comes from it, the work experience and the friendships (with your supervisors and your peers) can potentially be worth their weight in gold down the line. If I had to do it all over again I would've interned for 3-4 semesters instead of just my last one.