I.S. is one of those games where the FIT we are always talking about here really comes into its own. That transition from hip to shoulder has to be smooth and seamless. If it isn't for you yet, practice that at home.
Are you also doing the up-to-three second delay? Adds another degree of difficulty.
IMO, you'll also learn to use more of your hips than before, so foot position is also important
Have fun and good luck!