Gentle acceleration is only half the battle. Keeping the speed down and (this is the biggie) not using the brakes unless you have to also make a huge difference.

On the highway, make use of the natural terrain. Even in FL, there are hills. Accelerate (gently) a little after the crest of a hill and get some coast time the rest of the way down and partially up the next hill. Resist the urge to force the car to maintain speed going up the hill, let it scrub off a few MPH.

In the city, it's all about looking ahead and managing traffic. I usually get better mileage in the city than I do on the highway unless I'm stuck in traffic that just plain isn't moving. As long as it's moving, you can do a lot of in-gear coasting and time yourself to the lights and the traffic flow so that you rarely need to use the brakes. Remember that in most modern cars, coasting down in-gear uses no fuel as long as the revs are above 1200-1500. Use that to your advantage. Rather than neutral-coasting up to the light and stopping for 30 seconds, coast-down in gear and use most (or quite often all) of that 30 seconds decelerating using no fuel rather than sitting at the light idling. And, if you're lucky, you'll manage to not come to a complete stop before the light changes and traffic moves, so you often won't have to start from a complete stop, thus saving more fuel.

Of course, some cars respond better than others. My wife's MINI Cooper is rated at 31 highway, and it's all I can do to get 34 out of it. I find that frustrating, but part of it is probably due to the automatic transmission.

I'm back to "playing the game" again lately. My last tank was 42 mpg average and included about 8 autocross runs. Just filled up today, no competition this month, so I'll try for... maybe 46-48. So far I'm at 48+. And lest you think that's just the car... it's EPA rated at 29 city and 36 highway.

It's definitely "gas mileage season" for me... no AC makes a significant difference in my car.