Audiences are often a little skeptical about a speaker’s message, especially if the speaker is addressing a controversial issue. You can build credibility with an audience by using reliable sources of information and backing up your statements with citations to trusted authorities.
You need to think about your presentation as though it was going to be written down on paper and distributed throughout the audience and their bosses. Throwaway lines which you assumed would just pass over people’s heads will end up being the bits that certain people remember – so be sure to keep a close eye on what you say and how you say it.
Often, people make the mistake of believing that the more they say, the better their speech is. Others, feeling that brevity is the soul of wit, keep what they say to a minimum. As with so many things, the truth lies somewhere in between and the key to making a presentation as powerful and as well-received as it can be is to say enough, and make what you say mean enough.
There is no point in fleshing out a presentation with extraneous detail which no-one will remember, and at the same time you should avoid leaving out anything remotely important so that your message is strong, coherent, and memorable.