It's so easy to make eggnog, I don't understand why any one would buy a commercial nog. They're never as good. Milk, sugar, eggs, liquor: so simple. I make a cooked eggnog. Started doing it during the salmonella scare a couple of decades ago and we decided we liked it better. We're not fond of the beaten egg whites so we use the whole egg and lactose-free milk. Fresh nutmeg is a given, and I also like a whisper of ground cardamon in it.
This year I made a non-dairy eggnog for some friends, using a blend of soy and coconut milks. To offset the nutty flavor of the soy, I sweetened it with brown sugar. Some rum and brandy, and my friends loved it. They were very excited to have a non-dairy version they could enjoy.