I have a chitload of gear cramed in the back of my cab i carry around that i'm too lazy to remove once winter is done that would likely help my fuel economy. I tried removing the air dam on the front of my truck, and lost nearly 1 mpg with more wind noise, but its easier to do an oil change with that thing out of the way. Overall imo, anything over 20 mpg is decent for a 4wd truck that weighs over 2 tons.The other thing people forget in this time of year that impacts fuel mileage.
Warm up idling. DON'T.
Start the engine, let the oil pressure come up, place into gear, drive off. No need to race the engine or WOT nonsense. Just drive easy for a mile or so. The truck will warm up in less time while its being used. Sitting in the driveway burning fuel is not beneficial.
tacojoel brings up a good point. Weight. It takes fuel to produce the power for hauling weight. So, remove any extra weight from doodads that you are hauling for bro points.