I'm no expert by any means, but with the warranty still in effect, you really can't do anything to the motor to let it breath or whatnot without effecting the warranty (main things done once warranty is over, based on this & other Powerstroke forums is the EGR & DPF delete, in conjunction with exhaust, CAI and tune).
Best thing you can do for now is to not romp on the skinny pedal at stop lights. I know it's really (really) tempting and fun to do from time to time, but easing into it and getting up to speed in a more controlled fashion will help the fuel mileage.
Yesterday after filling up in Colorado Springs, I rolled towards the house (NE Denver metro), putting on 187 miles and right now, my Lie-O-Meter is reading 19.8 (usually about 1.3mpg high when hand-calculating). Had I driven straight home and not incurred some city driving, it will be up in the 23 range (saw 24.6 for quite a while on the way home).
Unusual numbers for sure, but I've only had my truck for 3-1/2 weeks and am learning how to run the truck and not make my bank account look like a failed savings & loan. LOL