I was taught a splash of room temperature or slightly chilled water. No ice.Ice releases the aromatics in the single malt. 1 large cube is best. That's what I was taught at the distillery and I agree. It is better with a cube.
I will say that there is a real debate over this among scotch lovers. I don't mind it straight up but I prefer a cube. I'm going to email Shad and get his position.