The most important two minutes of your speech occur before you take the stage. Practicing nonverbal cues, or body language, will “optimally configure your brain to deal with a stressful situation," says Harvard Business School professor Amy Cuddy.

Jargon can complicate the most simple of messages. So why in the name of Web­­ster’s does the babble persist? “People use jargon because they want to sound smart and credible when in fact they … typically can’t be understood, which defeats the purpose of speaking in the first place,” says Karen Friedman, author of Shut Up and Say Something.

The South by Southwest festivals and conferences each spring feature many experts, some of whom are not expert speakers. One of them, Thom Singer, has written a book, The ABC’s of Speaking, geared especially for the shy expert. He has six recommendations: