Building connections have done wonders. I've had many people help me so much that I was able to pass on classes that I was likely going to fail on. Not only that but they have introduced me to extracurricular activities and opportunities to build my resume. Most people assume that having friends are nice and not much else but based on my experiences (and as an introverted person), it does make all the difference in the world.

You can save a lot of money on textbooks by shopping online, search the internet for pdf versions, and using the library for a copy. I follow this mantra: there's always a way around a new textbook from the bookstore.

Use Ratemyprofessor.com religiously. Don't just jump to one class when several options are available. One that you should consider is what the quality of the professor is. Doing this will make classes generally more tolerable and enjoyable.