I think that's mostly a matter of personal taste, although mint is popular; I have lemon balm that you could use for that - some people put it in iced tea. I'm not sure what else.
dried jamaica flowers are really good steeped in hot water, strained, then cooled and poured over ice with some sugar.
btw, it's not juh-may-kuh, like the country. it's pronounced sort of like huh-mike-uh.
i just bought a bag of them, along with some chipotles. the cabinet they're in smells great every time i open it. sweet, flowery, and smokey all at the same time.
BT is so right! Very popular drink here - it is made with hibiscus flowers. It's also very healthy. Tastes a little like cranberry juice, but better. I drink it all the time. I buy the jamaica already in a BIG teabag, so it is easier to make.