Both of those methods are lacking. For best iced coffee, brew a pot, pour half into ice cube trays and put the other half in the fridge. Put half a teaspoon of dark brown sugar in a glass, add cold coffee, stir until sugar is dissolved, add coffee ice cubes, and pour a dash of half and half over the top.
Or go buy a can of cold UCC coffee.
I like the coffee ice cube idea. I think what puts me off of cold coffee is the dilution that occurs from plain ‘water’ ice cubes. The water just doesn’t “go” with coffee and half & half.