There really isn’t much that can be said about Australian and New Zealand etiquette. They have manners, but they are much more relaxed and less formal than most other countries. (I heard Australians even go to work in shorts!)
In New Zealand, specifically, people may start with a formal tone, but such formality will almost certainly ease off. So will their volume. They are known for being more soft-spoken and not often loud. Where you rank in your business hierarchy is not usually important, except if you own the business, of course. And, although they might be part of the Australian continent, they greatly dislike being called Australian.
In Australia, specifically, the warm and friendly people use firm handshakes, and frankness and directness when speaking. And if they disagree with something, they almost certainly will speak out about it. Australians don’t care much for personal distinctions or class structure, since they are so informal. However, punctuality is much appreciated, just not critical. Australians also maintain their sense of humour, even when things are rather tense.
In South America, specifically, Spanish is spoken everywhere, except in Portuguese-speaking Brazil. Unlike Australia, South America is less inclined to worry about time and punctuality. Socially, they stand rather close together and touch (and expect to be touched in return), which is a culture shock for other countries. They eat their largest meal for lunch, around midday. Finally, social conversation and topics of a personal nature (namely talking about yourself) are often more interesting to them than is your business and company representation.
In Central America, Spanish is the most commonly-spoken language. Like their counterparts in South America, they also are less concerned about time and more concerned about you personally than as a company representative. Central Americans are also a closer-standing and touchy-feely crowd as well. They eat their main meals at midday.
In Mexico, specifically, it is customary to shake hands, as in most other places. Unlike South Americans, Mexicans do see titles as being important. Things not to do? Wear violet (their colour of death), joke about “Montezuma’s Revenge,” or placing your hands on your hips.
In the Caribbean, generally, handshakes are common, as is English, the primary language of the region. Granted, some residents do have rather intriguingly-accented English. Life’s pace is much more relaxed in the Caribbean, so table manners are much more informal, punctuality is not critical, exchanging gifts is not required, and business begins with extended social conversation. Business cards, however, are very important.
In Puerto Rico, specifically, gifts are exchanged, and opened immediately. Standing close is customary, and backing away is considered to be rather impolite. Although English is widely-spoken, speaking at least some Spanish is greatly appreciated.