I joined couple of mentor programs for university student before. My top recommendation for student is to pursue work experience on the field you like as soon as possible. The experience you gain will help both on the school and your further job prospect.
Go to office hours. Preferably, when you go you have an idea how to do the problems or have questions lined up. At the very least, it is dedicated time for specific classes. Seriously, few people show, but it is the best way to get help and make your face known to TAs and professors. Should be obvious, but go to class. Set aside non-work time. Many of the people around me who are happiest with their work have specific times that they don’t work. Common rules include “Saturday” or “after midnight.” Make class reading more effective by taking notes and writing down questions on what’s in the text. If appropriate, work out the sample problems or proofs, so things start to make sense to you internally.
Being productive in college – [Ask Metafilter]