A lot of times you will have to rely only on just the contents of your head and whatever may be conveniently around you to illustrate your argument. Sometimes, though, you will have other tools and resources available to you – especially for those arguments for which you will have the date and time known well in advance. Even if the tools are not specifically provided for you, take it upon yourself to arm yourself with whatever you can that will help you make a compelling case.
First of all, you should bring anything you can that will help you support your argument – any documentation or physical or picture evidence. There is always an element of doubt when someone just tells you something, but the proof of the eyes is very difficult to deny. A third-party testimony falls under this umbrella, and if you can bring someone else to vouch for you – a witness, an expert or someone else who holds similar views and is sufficiently credible – then by all means bring them in to back you up.
You may also have presentation aids available to you. Pen and paper, a black/whiteboard, charts, props and models and videos take your argument from the simply verbal and bring it into the visual. Using multiple sense organs like this engages more of the brain, making your argument much easier to absorb.
