Cream and Sugar: Tips for those who don't (always) like it black

It's occurred to me that most coffee connoiseurship guides don't acknoweldge the fact that many—if not most—coffee drinkers take some sort of creamer and/or sweetener in their coffee.  I'd like to break down that wall of (possible) snobbishness and collect a few random suggestions.

General, and most important, suggestion: unless you're having the same variety of coffee every day, take a couple sips of the black coffee before adding anything.  That way you can get an idea for what it might need.

Sweetened (vanilla-flavor etc.) soy milk - best for espresso drinks, due to the moderate natural sweetness of the espresso.

Unsweetened soy milk - best for chai (Oregon Chai and the like), due to the very sweet taste of the chai.  You don't need the milk to supply any extra sweetness at all.

Half-and-half - best for bright coffees like Latin Americans (those from Costa Rica, Nicaragua etc.).  The coffee needs to cut through the fat content here.  I find that espresso gets lost in anything fattier than 2% milk.