I have found that the easiest way to run a great race day is to do what the fast guys do. There are afew things that are key to a fast car.
1-clean it, find the cleanest ride & do what ever the owner does to his car to your car.
2-setup your car to be very fast. If there is a car on the track doing things that your car can't do then figure out how to make your car do those things.
3-watch the other heats & figure out the lines you can't take. There are alot of lines that will be effective, but when you find bad lines they are very noticeable.
4-get that adrenaline flowing and those nerves cracking. If you get nervous up there on the stand then just keep racing untill you realize that you got to spend your day playing with toy cars instead of mowing the grass.
5-find a radio that fits you. Some people want something that will practicly drive itself w/ gaudy throtle & steering inputs that just need a quick blip so something like an m-8 is perfect. Some people want very precise control so something with more movement is desired like a 3-pk.