In-class exercise for delivery
I have adapted this exercise from a public speaking book and find it very effective. I use this at the beginning of class. Create a series of cards listing specific delivery problems — talk too slowly, make overdone hand gestures while speaking, etc. I take volunteers and encourage them to ham it up. They can take a simple topic like how the semester is going or their spring break plans and then act out the behavior on the card in an exaggerated way. This gives everyone a good laugh, but also allows me to pose questions like asking the audience to guess the behavior on the card, how that behavior would affect a 6-minute speech, and as an audience member what would you think of someone speaking that way?
For my classes, students who volunteer for this activity receive credit for an impromptu speech.