This shows much of what we carry for leveling.  This picture was taken at Martinsville, VA, where we park for a week to attend a NASCAR race.  There aren’t any real campsites, just a field with roads through it.  Where we park is not level, to say the least.  I use 8 foot 2×6 boards for leveling.  I cut each end at a 45 degree angle, then cut three boards from each 8 footer.  I cut 2 three foot, and 1 two foot length.  This typically gives me two leveling boards and one board for under the jacks.

This picture shows the camper level, just after the final back-up.  There are several things about this stack that beginning RVers should note.  First, note that the boards are staggered at the front so that you can back onto them easier.  Second, notice that by cutting the ends at 45 degrees, the boards mesh better and stay together under the weight.

Third, notice all the boards set at right angles to the leveling boards with more boards under their ends.  What this does is act to level the stack, so the camper is not sitting on anything that is tilted.  This keeps everything safe while the camper is parked.

I know that there are many systems available for leveling, but I have used these boards under various campers for many years in many situations.  I find them to be versatile as well.  As well as using them under the wheels, I use them under the jacks, picnic tables, stoves, or anything else that needs leveling on a campsite.

One final note about putting a camper on boards is this: if you have a four wheel drive, put the transfer case into low range.  This allows you to maneuver largely without using the throttle, and prevents jerky motions.  Slow movements also give you more time to correct and think about what you are doing.