ok i do that a lot and its really fun whats u know how to do it...just skip then everytime u put ur legs up u stick it out a lil more then how u normally skip, and if u do it right the ball should bounce a little more forward then the leg u hit it on, and u should be able to just skip along with the ball,

another way u can do it is u can not skip and just keep on dribbling it with ur knees,....what i do when i do that is u first drop the ball and with one of ur knees bounce the ball with that knee right after that u switch feet and bounce it with ur other leg its faster but easier