Visualization is the key word here. Estimate approximately where you want to land and visualize it backwards. Then when you setup to land, if you're way off from that visualization go round again, until it's pretty close. After you get your plane back on the ground, make changes to the visualization to correct for wind, rate of descent, trees, etc.

Also are you flying off grass? I've found that the best way to avoid the bumps on grass is to slow the plane WAY down (like near stall) before touchdown. Bumps in the grass have a tendency to put the plane back into the air if you're too fast.