Answer:
There are many different types of visual aids. The following advice will help you make the most of those most commonly used.
PowerPoint (or equivalent)
Microsoft PowerPoint is probably now the most commonly used form of visual aid. Used well, it can really help you in your presentation; used badly, however, it can have the opposite effect. The general principles are:
Do Don't
use a big enough font (minimum 20pt) make it so small you can't read it
keep the background simple use a fussy background image
use animations when appropriate but don't over-do the animation - it gets distracting
make things visual use endless slides of bulleted lists that all look the same
Overhead projector slides/transparencies
White or black board
Paper handouts
Flip chart
Video (DVD or VHS)
Artefacts or props
