Never, but never (remember stoning) show a slide…
Never, but never (remember stoning) show a slide and then apologize for it. […] Don’t show bad slides! They never help; they always hurt.
When you are giving a paper, you are an actor on a stage. […] put on a happy face and kick ass … or get off that stage.
Jay H. Lehr in his highly recommendable paper Let There Be Stoning!