"Taking the ball down the leg side is the most difficult catch for any wicket keeper.
Try to see the ball on the offside of the batsman for as long as possible before moving down the leg side and seeing the ball late into the gloves. Your feet will need to shuffle very quickly across to the leg-side in order to position your hands to catch the ball.
Notice the large catching area of the wicket keeper’s gloves when he takes the ball. This is because his shoulders and hands are relaxed whilst moving."