This advice and more can be found in Finding Your Voice:
In his book, Sein Language, Jerry Seinfeld talks about performing: Remember, timing, inflection, attitude. That's comedy.' Rehearsal is the time when you discover the suitable timing or rhythm for your speech. Even if your lines are lightweight in the humour stakes you can do exceptionally well if you grasp the essentials of posture, timing and pause. Mrs Mary Atkins, Speaker and Author.
You don't need to be a stand-up comic to be a roaring success as an after-dinner speaker. If you are not a natural comedian, don't think that you have to set yourself a-joke-a-minute target. The audience is warm and mellow by the time you speak and ready to laugh at the slightest implication of humour. Getting a smile, laugh, chuckle, chortle or guffaw for a funny line that you have created is one of life's great moments.