Is your bike skidding, or do you mean the cleat on your Speedplay is skidding across the road?
If I clip out early, in anticipation, I just rest my foot on top of the pedal. Yea, it slows you down, because you can't really pedal, but mostly in these situations, you are coming to a stop. Otherwise, you will ruin your cleats by dragging your foot on the road when you unclip.