Agree, with feet movement. small quick steps are must just like being in windy conditions. You have to remember, as Mats Wilander always tells you,
"your feet and movement is just as or more important as having beautiful strokes and having great shotmaking" It doesn't matter how beautiful your shots are if your feet doesn't move well.
Babolat Pure drive 2012, 55 lbs, Kirschbaum Proline X / X-1 biphase. Nalbandian backhand and Nadal forehand.