riffling is totally fine, that's the way i do it too. The killer secret to make it look good is to move your right hand away (drop it to the side, or gesture, act yourself somehow) and say something, to get some dead time from catching the break to lifting the double while the left hand stays still and does nothing (very important).
That helps you to catch a breath if you're shaking, and relax whenever possible.
The pinky count: i don't know how you do it, but it may help change the grip, i reposition my hand with the left index more to the corner, and in that way i can get the pinky more up toward the top. But again, lifting the back of the card, pausing, and doing the double is just too comfortable!
The dip seems a bit unnatural to me, it sure help the angles, but it communicates that something is going on.
The action is turning one card, if i'd wanted to add a big motion i'd just twist the deck while turning the card instead of dipping.