Go to different dealerships before settling on one. A different dealership might be able to get you a better price on the car you want, and may be running different promotions. Try three or four in your area, and even if you have to travel a bit farther, it may be worth it.
Do not allow yourself to buy the first car that you see, even if it seems like it would be perfect for you. There are so many vehicles out there for sale that buying the first one may cause you to lose out on making a much better deal on a car you may like a bit more.