Things you'll need:

1.shovel
2.hoe
3.flat clear area to build jump
4.wheelbarrell (optional)

Now how to build the jumps:

1. first find a spot to dig your dirt up from
2. second pile the dirt at the spot that you want your jump
3 keep piling dirt in that spot until you get the height of the jump that you want, don't make to big if you can't jump it.
4. take your shovel and from the bottow of the ramp scoop up and down and make a curve on the jump.
5. build your lip this will help throw you up in the air so that you can pull off your tricks.
6. build a landing about the same size as your jump but wider. Don't make it to long of a gap to where you can't get over it or else your result could hurt if you don't get enough speed.
7. as soon as your done with these steps, your already to jump.

last but not least have fun and always wear a helmet.