5. Conduct as many "Murder Board" simulations as possible
The "Murder Board" is a rigorous practice session, similar to a flight simulator used for training pilots how to deal with in-flight emergencies.
Select no more than four people to be your simulated audience, appointing one of them to role-play the senior person. Share with them all the intelligence you have gained on the group/person receiving the presentation. These four people will then role-play these executives. Their comments, questions and criticism help you correct your style of delivery, find the gaps in your knowledge, and anticipate questions and objections.
Prior to convening this Murder Board (a term with origins in the US military), practice solo with a tape recorder and, if possible, a video camera. These tools should then be used in the various Murder boards.