hit him while he has the starman, i think its the same timing for shield
I don't believe this is true, actually. The shield and the starman have different hitlags. You need to just put a rubber band around a second controller to practice shield pressure. That's all. From what I've learned from ArcNatural, these are the different timings you need to get used to for shffling:
Not hitting your opponent.
Hitting your opponent.
Hitting your opponent while shielding.
Hitting your opponent while he has the starman or otherwise invincible.
And all of these change for the ICs.
Best way to practice the second one is to put another controller in on Bowser, handicap set to 9 (yours set to one) and just go at him for a while. Same thing for shielding, but just put a rubber band on the other controller. And for the last just put starmen on medium and make sure he gets them. No use in doing it in training mode. No c-stick messes with you if you're used to using it.
And I'm sure you can figure out how to practice shffls without hitting your opponent.
This is all what I've heard, though, so someone correct me if I'm wrong.