Most people are used to moving with their shoulders to the left or right within
the control frame as a means of shifting their weight. When aerotowing you need
to be sure to move your whole body, as though it were a straight board, pivoting
around a point about three foot in front of the center of the control frame. If
you want to move to the right you move your whole body as though it were a
board, to the right with your toes furthest to the right. This means that your
head will stay fairly close to the center of the base tube, while the rest of
your body is to the side. You don't just shove your butt to the side, but your
whole body.

If you don't do this, and move with your shoulders the upper part of your body
and your head to the side, the glider will yaw to the other side. Move this way
to the right, the glider will yaw to the left.

For example:

In the photo (not a high resolution photo) you can see that while
the pilot's head and chest are to the pilot's right, his legs and feet are to
the left. This means that the glider is going to yaw to the left. If the left
wing is touching the ground, that's certainly not going to help.

Jim Prahl <<arcjim10>> writes:

In this particular incident I did not see the angle on the cart or
body position prior to the launch. If the glider was trying to launch with a
higher than normal angle, make sure you don’t lock your arms during the initial
roll. Let the tow line pull you to your chest over the control bar into the
position it would be at trim or best glide. Hold that position. The tail usually
raises and all goes well.

Also in the photos so far, really not much weight was moved with the cross
controlling at the beginning. When the right wing rises at launch, and not being
a coordinated turn, your lower body wants to hang to the left and you have to
physically get more weight to the high wing. You also have to resist the towline
from pulling your shoulders over.