In my line of work, especially during recruiting season, I've had the privilege to meet and talk to young college students; they are either interning or interviewing to be interning, or sometimes they just want to talk to someone in the industry. I'd like to share some career advice that I've provided to them, hopefully these are useful for somebody.
As many people say, college is the best time of your life. You don't need to worry about jobs, no need to worry about bills, or how you're gonna pay for your kid's school. Well, it's all true as advertised. Enjoy this phase of your life, you will not get another chance at it. No need to burden yourself by finishing early, unless it's for some other reason (e.g. financial consideration). Take some extra fun classes. Take philosophy, art, music history, whatever you can enjoy. Perhaps just sit in and audit these classes (most professors allow this).
It is a big world, but it is also a small world. Sure they may be your schoolmates now, but in 10 years they will be a Skadden lawyer, a nephrologist at Mass. General Hospital, an associate producer in Hollywood, a centerfielder for the Oakland A's, and a firefighter at Philadelphia FD. Stay in touch with them -- I personally prefer fantasy football as a low-investment means for keeping in touch. Facebook also works well.
Take business classes
Most importantly, take basic accounting and finance classes. Also take business writing, if such is offered. Why? Because no matter what you end up doing in your career, these will be useful one day. Who knows, maybe you may end up as entrepreneur. Basic business knowledge is important for everybody.
Get your read on
Again, emphasis on business-style writing. Read equity research reports by banks, market wraps, and business journals on tangible topics. Acclimate yourself to how business world writes. Business writing is not the same as college essays; you need to be concise, concrete, and professional. You may never again need to write a 20-page legal analysis on the Enron scandal, but you will probably need to write a 2-page teaser explaining your business model to your bank.
Spend summers wisely
Contrary to popular beliefs, not securing internships at Microsoft or Goldman Sachs is not the end of the world. You do have some liberty on how to spend your summers. Yes, ideally for the one after Junior year you should have an relevant internship at your preferred field. But at least for the first two summers you can do something interesting, as long as you make sure it's productive and worthwhile. Work with a professor, find yourself a professional mentor, which could be anyone like a relative -- doesn't need to be Steve Jobs. Spend part of your summers doing something interesting: take up cooking, learn martial arts, or anything to make yourself wholesome, refreshed, and ready for the new school year.
Give back when you're done
It doesn't need to be monetary if you can't, most of us will be too busy building a career/family and paying our student loans. Promote your school. Conduct alumni interviews. Come to school events nearby. And lastly, keep in touch with your favorite friends and professors.
Best of luck!