1. Don't drive your car.
2. If you do drive, know your real MPG so you can have a baseline.
3. Keep your car maintained. If you keep up with it, you can use the cheap stuff
4. Remember that your car is only a tool to get your from one place to another.
5. Your tires are important. Keep them rotated, blanaced, inflated & aligned.
6. Coast whenever possible.
7. Turn off the car at railroad tracks and long red lights.
8. Simplify your intake. I've never seen a car that didn't improve FE by removing ducting.
9. Get some instrumentation to keep you honest with yourself.
10. Don't obsess about it. It's important, but not the end of the world.