Use conflicting sound and visuals. Find a running-gag sequence, and drop it in every three or four minutes. Play the voice of someone the exec hasn't seen in 30 years. No one's life is all laughs. Put in a few minutes of emotion and sentiment.
Humorous interludes gain strength from contrapuntal style changes.
Those responsible for reserving your roast room may forget about the three or four hours you need to setup equipment and rehearse presentation cues. Twenty to thirty minutes of tape, plus 20 minutes of speeches, seems about right to me. It's a nice move to later give the basted boss an album holding photos, the video, guest book signatures, etc. Finding meeting producers who won't use your business to learn theirs is a lot harder. Next month I spell out some screening tips.