Levelling an RV is key to a good night's sleep and a properly functioning RV, so levelling ramps are very important. You can certainly buy level kits, but they are pricey, and there's no reason that you can't make your own with just a little bit of time and ingenuity.
Assemble your equipment and supplies. The 2x4s will form the ramps, and you will attach them to each other with the nails. The power saw is for ripping the wood into appropriate sizes and shapes.
Cut the wood into chunks. You will need ten 10-inch 2x4s, six 6-inch 2x4s, ten 7-inch 2x4s, and two 4-inch 2x4s. Cut the ten 7-inch 2x4s in half lengthwise to create 16 2x2s. Take two of the 6-inch 2x4s and cut them in half on an angle through the wide side, starting at the 1/8th of an inch mark, creating four chocks. These will form the ramps of your levelling blocks. Finally, cut the four-inch 2x4s into smaller chocks.
Frame two 10-inch 2x4s, lying flat, between two of the 2x2s. Nail the 2x2s into the ends of the 2x4s, forming a large block. This is your basic levelling block. Repeat this process with the rest of the 10-inch 2x4s, until you have five basic levelling blocks. Set three of these aside. The other two you will build into taller levelling blocks. Nail two 6-inch 2x4s on top of the 10-inch 2x4s, starting at one end, so you have a block that is two 2x4s deep. To the thinner end, nail two of the 4-inch chocks.
To use the blocks, simply place them behind the wheels of your RV and drive over them. Place the longer chocks against the levelling blocks to form a ramp so the RV can easily climb onto the blocks.
Set up all the ramps you plan to use and drive onto them at once. Place the ramps so you do not have to steer onto them, but rather drive in a straight line.
Do not use more than two tall levelling blocks at once. Do not put all four wheels on levelling ramps at once. If you are not in the centre of the levelling block, drive off and reposition.