Good list, the thing on here that I think people overlook the most is tire air pressure. Well, that and not driving aggressively (heavy acceleration, constant speed fluctuations, etc.)
You know what I found works? Turning the snorkel head around backwards! I literally (not figuratively, but really literally) doubled my mileage by turning my snorkel head around backwards.
Originally I had turned it around because I had to drive almost 2 hours in a blizzard and didn't want to suck snow the entire time. Forgot to turn it back around the next day and noticed that instead of using just over 1/4 tank on the drive to work, I used 1/8 tank. Thought it was a fluke, but I've left it that way for about 2 weeks and regardless of how I drive, I'm continuing to use 1/8 tank of gas for the 35 mile drive. Hell of a lot better than 1/4 tank in 35 miles!!
Example using nice, easy to work with numbers:
If your engine knows that it needs 1,000 CFM of air, then it knows it needs to use 100 ounces of fuel. If you're cramming 2,000 cfm of air into it, then the mass air flow sensor is reading that and telling the computer to dump 200 ounces of fuel into the system, regardless of the fact that the engine really still needs just 1,000 cfm of air and 100 ounces of fuel.