I find putting it in a cup, then using the cup to pour it down my throat works best, and creates the least amount of mess. I've heard some enthusiasts say lapping is the only correct way, but I don't notice enough of a difference in enjoyment to bother.
A friend suggested this to me once, but I found it simply went cold and the corresponding tongue-action needed meant it took longer to drink.
NATO standard: Milk, two sugar.