I sometimes climb in the gym with a partner who outweighs me by about 50%. When he's leading and falls from above his protection, I can get pulled up to the first clip. If he's not very far up, this could lead to the dreaded "ding-dong" effect, where I get pulled up and collide with him as he falls.

What effective strategies are there for preventing this? I can try to stand out of his line of fall, but that won't help if I'm simply levitated directly up to the first quickdraw on the wall.

Sometimes when I'm climbing a route in the gym, and I feel confident of the first few clips, I start by clipping a quickdraw that's off to the side, then skip a clip, then clip into the third clip on my actual route. (I skip the second clip because I don't want the rope to go around a sharp corner, which would give a lot of rope drag.) Doing this eliminates the possibility of a ding-dong, at the expense of possibly having a ground fall before I reach the third clip. But this is not something I would ask a climber to do for me when I'm on belay.