Become an authorized user on your parents' credit cards.
If you don't want to or can't open your own credit card account, consider asking your parents to add you as an authorized user on their cards. If they have good credit, you'll be piggybacking off their positive credit history, which can boost your score.
Choose responsible roommates.
If you decide to live in an off-campus apartment, choose responsible roommates you can trust. Since your name is on the lease and you're paying utilities together, it will hurt your credit if they're missing payments or not turning in the rent on time.
Pay your bills on time.
Just like with credit cards, this is imperative. Missed or late payments from your Internet, cable, or cellphone bill can damage your credit report. Even things like doctor bills, unpaid library fees, parking tickets, or school fees not covered by loans could get sent to collections and harm your credit.
Don't co-sign for your buddies.
There are plenty of ways to be a good friend in college, but co-signing for anything should not be one of them. The second your friend misses a payment, your credit is negatively impacted. Regardless of how responsible a friend is or how secure their job seems, you can't control if they stop paying down the road.
Check your credit report.
Keep an eye on your credit. Annualcreditreport.com allows you to check your credit report from each of the three main credit reporting agencies once per year. Space it out so you're checking each report once per year.
Monitoring your report is essential in building a good credit history. You might see an account you didn't open or other suspicious activity that turns out to be identity theft. The sooner you report this, the sooner you can have it removed from your report and improve your credit history.
Besides identity theft, it's also a good idea to monitor for mistakes. There could have been a glitch in a company's system that reported your payment as late when it really wasn't, for example.
Reduce your hard inquiries.
As mentioned above, applying for several new accounts at once can harm your credit. If you're looking for a private student loan or if you're shopping for a car, do your searching within a 14-day period. Anything within this time frame will count as one inquiry and harm your credit less.
Protect your identity.
Even if you know the people you live with very well, you don't have control over their guests when you're not around. Keep your Social Security card, bank account information, driver's license, and other important documents in a secure, safe place that people can't access.
When using a public computer or an unsecured wireless network, as is common in college, avoid paying bills, shopping online, or other activities that could leave you vulnerable to someone using your accounts or information to open their own account.
Keep your information up to date.
You may move multiple times while you're in college. Any time you move, be sure to change your address on all your accounts and with any bills you pay. You can also have your mail forwarded in case something slips by you. Bills going to the wrong address could mean missed payments, late fees, and a negative result on your credit.
Besides changing your address when you move, also be sure to cancel all your accounts associated with that address or remove your name from any accounts shared with roommates, such as utilities, cable, Internet, and of course, the apartment lease.