the ego change is where you grip it between the index and thumb and pull with the pinky, but the cardini a mechanics grip and pulling with the middle or ring, I'm not sure which one.
And as for the tips,
for the ego, have a firm grip between the index and thumb, close to the tips.
for the cardini, put no other fingers on the deck, keep a grip, but don't let the tips of the fingers overlay onto the deck, and slightly bevel the deck towrds the ring, for easier lift off.
and for both of them then keep as light pressure as you can on the deck, but slightly more pressure with the levering finger, also remeber that you only have to lever it fast, to get it out of vision,also the levering finger pulls from the ace of the deck, to the side of the deck for a faster levering.
this is all I can think of other than practise.
if it's exposure delete this.
hope this helps,
tom field