As you probably know, the rules and expectations for communicating well differ from culture to culture. U.S. Americans tend to expect direct communication so speakers are likely to get right to the point and state their thesis during the introduction of the talk. Many other cultures, including those which are considered collectivistic, consider the directness of U.S. Americans are blunt and inconsiderate. For many African and South American cultures, speakers are expected to be more subtle and less direct than U.S. Americans. Many Asian cultures believe that maintaining social harmony is far more important than directness. Likewise, the Mexican culture prefers indirect politeness to the U.S. manner of speaking.
Check out the scholarly but readable Princeton University’s udpated 2004-2005 Handbook on Exploring Cultural Differences at http://www.princeton.edu/~sap/handbook/chapter-9.html. Offered as part of its Study Abroad Program, this site includes sections on Culture Shock, Cultural Stereotypes, Fitting In, A Note for Women, Race and Ethnicity, Sexuality, and more.
Joseph DeVito offers the following suggestions drawn from the Task Force on Bias-Free Language of the Association of American University Presses for avoiding sexism heterosexism and racism:
But not all agree on how to handle and address the complications of cultural differences. See writer P.J. O’Rourke’s interesting commentary on the Task Force publication, “Perfect Form: The Guidelines for Bias-Free Writing” by Marilyn Schwartz at http://www.findarticles.com/p/articles/mi_qa3814/is_200201/ai_n9035180.