bluegargantua

Note that the dice always come out with the first die picked up on top. As they're picked up the 'swirling' motion of the cup will make each die want to be along the same vertical line moving along the edge of the cup. So they'll naturally fall into a column. Getting them to stop that way is probably hard - looks like a short, sharp motion to arrest the spin.

The physics seems to be simple - the practice isn't, I'd imagine.