If the campsite is generally flat then here is my sequence of steps:
1. Assuming front to back is close enough to level side to side I let air out of one side of the airbags on the truck. That gets me an inch or two left to right and solves the problem probably 70 percent of the time and it only takes a couple of seconds.
2. The next go to method is to drop the jacks and attempt to level with them but only if it is an inch or two either side (I don't bother to undue the tie-downs because I'm not raising it off the bed).
3. If either of these two methods won't work for the site in question, out come the yellow Lego blocks.
Most of my travels have been to locations where I can get away with minimal effort through the steps above. I do have plans to purchase more leveling blocks (I think I have 10) because there have been times where I wasn't able to get high enough by a couple of inches.