So I am going to ask sort of an obvious question here, but maybe the answer isn't so obvious. What is the right way to "roll" the die? I was thinking of just dropping casino quality die from about 10cm above a hard surface. Is this the best way? Is there a best way?
There is a belief among some people that if you are rolling dice repeatedly many, many times, you can get into a bit of a rhythm such that you start to pick up the dice in almost exactly the same way, and release them in almost exactly the same way multiple times resulting in patterns in the results.
Personally, I suspect that this is generally unlikely, and if it is possible, it would be be unlikely that anyone could predict what your personal patterns would be.
However, if you want to be certain that you aren't accidentally creating predictable patterns in your rolls, I'd suggest placing multiple dice into a cup. cover the opening and give the cup a few firm shakes. Then dump the dice out onto a flat surface. The act of the dice bouncing off each other and the cylindrical sides of the cup should be sufficient to randomize the results even if you both drop them into the cup and shake it in exactly the same way every time.