As I approach these two tight trees, my aim is to carry as much speed through them as possible. Because of some braking bumps leading up to them, I am able to maximize my speed by getting airborne and turning the handlebar, which effectively decreases the width of my machine and "threads" it through the small gap.
In the approach to these trees I slow down a little earlier than usual so I am at the right speed to be able to gas it and use the last bump as a small jump | 
Once the front wheel leaves the ground, I turn the bar to the left, providing more gap between the end of my bar and the trees. Notice that my body is leaned slightly to the right and the bike to the left. As I'm moving forward, toward the trees, the right side of the bar is now slightly closer to the trees than the left, but the right-side bar also has enough gap widthwise to not hit a tree trunk | 
With precise timing, as the right-side bar passes the right tree, I will begin leaning the bike to the right, counteracting this movement by moving my upper body in the opposite direction. This will gain clearance for the bike from the left-side tree. It's important to continue gripping the motorcycle with your knees, and to be aware that the rear wheel of the bike doesn't swing out far enough to hit the base of the left tree. |
I land rear-wheel first with the power on to keep the front wheel light and tracking straight in these sandy conditions. The same basic technique can be used on flat-approach situations by doing a wheelie instead of a jump. | | |