Once very important tool every camper needs is a set of leveling blocks. Most sites you pull into are not level, some are not even close at all! Leveling blocks can be as simple as a 2×8 piece of lumbar cut into 12 inch lengths, or you can buy a pre-made set of leveling blocks. I actually use both types. The pre-made set of blocks I personally use and highly recommend are the Camco leveling blocks shown below. They are very versatile as you will see in the pictures coming up.
When I first pull into a campsite I will always check to see if the camper is level from side to side. Most of the time the camper will be leaning to one side or another, and I want to fix that problem before I even unhook from the vehicle. The easy solution to level your camper side to side is to put the low wheels on top of the leveling blocks as show below. This is a much better option than using the jacks on your camper to level it. Those jacks are intended to stabilize the camper for when you are walking, they are not intended to support a ton of weight. I have bent jacks in the past, hopefully you can learn from my mistakes!
Once I have the camper level from side to side I will chock the wheels and then use my wood leveling blocks to put under the tongue. I will typically use six blocks so I don’t have to crank it as far, but you could get away with using one or two. If I am on a very steeply sloped campsite I can always use less blocks under the tongue and have extra to use elsewhere. I could have easily used the Camco blocks under the tongue as well but I already had the wood ones. Once the wood starts to fall apart I plan on buying another set of Camco blocks. I do like them better since they are very lightweight, just as strong, and will last longer. They also all stack together and have a nice carrying handle.
The last thing you may need leveling block for is the jacks. While is is not required at most sites, it does make it easier to reach the ground, especially if you are on a steep slope front to back.
Make life easier on yourself by having a set of levels on the outside of your camper. You can get them for really cheap and it takes all the guess work out. They are easy to install, just make sure the counter-top in the camper is perfectly level, and then install the levels on the outside near the tongue. You will want one for left/right level and one for front/back level. I have mine installed on the front left corner of my camper.