j,
I've found the best way to get the best amount of hip bump is to make the first action from the top an attempt to raise my right heel off the deck, while the weight is still on it..
What you'll find is that the intention of trying to raise that heel kicks your left hip laterally left and you get automatic weight transfer.....your body reacts to the right heel the same as when you are walking....as your right heel raises, your body knows it needs to secure the left foot and transfer the weight there (otherwise you'll fall over........

)
i don't like conciously thinking of weight shift as there is a tendency to overdo it...
Remember tho, you must keep your head steady behind the ball at the same time...