How do I improve the way my 1997 Ford Taurus runs?

I recently purchased a 1997 Ford Taurus and it has about 80,000miles on it. It runs great and smooth. Sometimes the engine will make uncharacteristic noises but not all the time. I was wondering if anybody has any tips in improving the the way my car can run. I do oil changes every 3,000 miles, but is there any other way to make my car run at its highest level. As for instance, is there any types of fluids that I can add to my car to make it run better or any parts that I can replace to make to run better. Any suggestions will be great. I recently graduated college and this car has to last me a good while until I can find a good paying job. THANKS for your help!!