Travel earlier than you “need” to, in case there are flight or traffic problems. When you arrive at the hall, do a sound check to see how close you should be to the microphone (do not hold one, if you think your hand may shake). If you will have to use a lapel (lavalier) mike, practice walking around the stage and returning to the podium as you need to look at your notes. Make sure any equipment you need to use actually works (always have an emergency kit of spare items you may need, as well as a backup plan if that is not enough). Practice getting on and off the stage without tripping. Make sure there is a glass or bottle of water at the podium (not cold, as that will freeze up your vocal cords). Determine if the air conditioning or heating is at a comfortable level for as many people as are expected in the room (better that it is a little cool, since people get drowsy when too warm).

And most important, carry a spare copy of your speech in a pocket, in case your luggage or briefcase gets lost.