A set of slides can be a great visual support of your presentation. But they should never be the main focus of your performances. Here are 3 tips to make your presentation truly a visual aid.
Put little text on your slides
There should be just enough text on a slide to give the audience an idea where you are in your presentation. To get the real content they should have to listen to you (hand outs and speaker notes are useful documents but should not be on the screen behind you).
Don't look at the screen yourself
If you wan't the attention from you audience make sure your own attention is with them. So don't look at the screen behind you unless you want all the attention there. For example when showing a movie clip. In these cases really look at the screen as if you see it for the first time and don't talk.
The presentation can be switched of
If you don't need a visual aid the beamer can be switched of or a black slide can be added to your presentation (or try what happens when you press the ".” button while running a PowerPoint presentation). This will help you get more attention and if the projector is placed on a table it frees up a lot of space to move around where you otherwise would block the projection.