Try other surfaces like windows, walls, and rugs that can be temporarily lettered. Be original in your choice of materials. Match them to the mood of the show. But always remember to keep it simple. Write what you want to say when various slides appear on the screen.
Informal remarks are usually best.
Refer to any planning cards and notes for ideas, and keep these tips in mind. Make your comments short and snappy. Remember, you don't have to, nor should you even want to, talk over every slide. Let slides or slide sequences speak for themselves whenever they can. Build word bridges from one section to the next.