I'm not sure where your from but Crooked creek used to have a nice log in front of the house for practicing this skill. It had a low side to roll over, a mid height to practice proper technique and a tall spot that you had to get right or go OTB. Your KDX should have no problem, some would say it is the ideal bike for the job.
And you don't need a lot of land to build skills. I spend a lot of time doing first gear full lock figure 8's in my driveway and riding over landscape timbers like a balance beam and hopping them diagnaly. There is a steep drop off to my road that I also do circles on and slowly ride up and down. The biggest thing I think is learning to stay centered on the bike, you'll be amazed at what it can do if you just stay out of the way.
And you don't need a lot of land to build skills. I spend a lot of time doing first gear full lock figure 8's in my driveway and riding over landscape timbers like a balance beam and hopping them diagnaly. There is a steep drop off to my road that I also do circles on and slowly ride up and down. The biggest thing I think is learning to stay centered on the bike, you'll be amazed at what it can do if you just stay out of the way.