As aids to observation, we can look for behaviors that to us are strange. So simple that it is overlooked, we can ask a member of the group for an explanation. Cultural informants are precious. Research into ethnographies of the target people can be invaluable. Many are not done from a Christian perspective.
Country studies published by the U.S. government are very thorough.
They are now on CD Rom discs. Article data bases provide the most current information, apart from shortwave reception of national news services. Dissertations and theses, as well as books, are other sources. Cross cultural ministry is like picking one's way through a mine field. With great care we probe for the mines, knowing that a situation may blow up in our face if we are careless.