Like it or not, you're going to have to economize. Start off by packing underwear, say the college student-authors of College Survival. Underwear is always the first thing you run out of. You don't want to be doing a wash every five days. For other clothes, try to choose pieces that can be worn interchangeably.
Jeans go with almost anything, so pack a few.
Include some solid shirts that you can accessorize with blazers or scarves. And, don't bring anything that you don't wear regularly. Also, bring one heavy coat and one or two dressed-up outfits. If you own a suit, bring one, but you probably won't need it your freshman year. Eventually, however, there will be occasions where you'll attend a job fair or conference, or go on a job interview.