Clean it Up
Giving your laptop (or desktop) a thorough cleaning is essential to extending its life. Back up any data you may already have stored (on an external hard drive or portable flash drive), organize your desktop icons, empty your computer's trash on a regular basis, and clear out any programs you don't use. This will help free up space and keep you on the fast track to productivity.
Practice proper shut-down habits
Shutting down all open programs, and putting your laptop to sleep instead of just closing the lid will help your computer stay cool and safe while in transport.
Protect your investment
If you're going to be lugging a laptop around campus, make sure it's protected in a padded case!
See the rest of my tips after the jump.
React to spills immediately
Water is not your computer's friend. Try using the 'ole rice method to bring your laptop back to life after a spill: take out the battery, dry off the laptop as much as you can, and pop the whole thing in a bag of rice. I've heard it works wonders!
Keep it out of the trunk in all climates
Just like liquid, heat, cold, and your laptop are not good bedfellows. Not only does both heat and freezing temps suck the life out of your battery, but it causes damage to your internal components. Your hard drive can expand and fail in the heat, and freeze in the cold if left unattended. Be sure to take your laptop with you instead of leaving it in your trunk!
Use kosher cleaning products
By kosher, I mean LCD-approved! You can't just use any old household cleaner to spruce up your delicate laptop screen and body - stay away from any all-purpose household cleaners and anything containing acetone, ammonia, or alcohol, which will strip away your LCDs protective coating. Use a soft cloth (like microfiber) to wipe down your monitor and screen, steering clear of paper or bath towels, which will cause scratching. If a dry wipe down won't cut it, try using distilled water, or a 50/50 mixture of white vinegar and distilled water, and use light, rapid circular movements to help reduce streaking.
If you do decide to get a new laptop, make sure you're disposing of your older model the right way. Suss out recycling centers in your area, resell it, donate it, or just drop it off at Best Buy for fast and easy recycling. In any case, be sure to wipe your hard drive of any personal information and do a factory reset to make sure you're clear.
Create a productive environment
A proper work space can help you stay focused and productive all year long, so why not invest in a good desk like the Vika Veine ($99), that has a flip-top lid to hold your papers, and cable outlets to keep your cables managed.