Start a list of ways that help you get the best gas mileage.
1) Don't gun it off the start. Slowing accellerate.
2) Watch out for spinning tires in the rain. Rain and wet roads can cause up to a 10% fuel loss because of spinning tires.
3) Keep your vehicle well serviced and keep those air filters cleaned.
1) Keep highway speeds down as well. Traveling 75-80MPH+ KILLS your MPG. Drop back to 65 MPH and set CC and you can see 2-3 MPG gain. Even more if you are really nuts and go 85-90+ out there. Example. My 05 Silverado EC 4WD 5.3L HO w/ P265/70R-17's and 3.42's would get me 21-23( depended on conditions and highway traffic ) MPG highway if I set CC at 62-65 MPH. 55 is still the most fuel efficient highway speed but no one goes that anymore. So, keep it to 65, or 70 max, and you WILL see a big MPG gain over going 75-80MPH+. I know in my 05 just going up to 70-75 MPH dropped me under 20 MPG. Keep your RPM range in the 1500-1800 range for optimal MPG highway. For every 5 MPH you travel over 60 MPH is like paying approx 20 cents more p/gallon of gas( EPA estimate ), Slowing down to 60-65 MPH can save you anywhere from 7-23% in fuel economy( EPA estimate ).
2) Keep your tires properly inflated. Underinflated tires will hurt your MPG and cause premature wear as well.
3) Run synthetic fluids where ever possible. The reduction in friction and heat leads to a more efficient engine and drivetrain.
4) Remove all of the JUNK from your vehicle you don't actually need. Fort every 100lbs of extra weight you remove you can see approx a 2% fuel savings( EPA estimate )
My #1 and Steve's #1 are the two biggest ways to increase your MPG while driving however. SLOW DOWN! I also completely agree with Cableguy about llimiting idle time. That really eats up your fuel and hurts MPG in a big way. Big V8 engines are effected much worse by idling than smaller 4 cyl engines.
