I bring along a sharpie and a tape measure for pointing and marking locations. A few business cards. I bring manufacturer literature that is intended for the end user however I don’t usually end up using this. As of late I have been using a PowerPoint style presentation shown on a laptop that basically shows all the services offered, a few quick pictures, and a brief description with no technical terms, all catered for an on-the-jobsite showing. One of my issues is skipping over the fundamentals of a system, assuming that the customer knows something about how it would work, but in reality they don’t. So the slideshow really sets a foundation and if we need to get technical from there we can.
I like to invite customers to my own home or homes we have done in the past, which does a lot better job showing the services offered than any type of document or materials meant to be shown to the customer.
When I’m showing the proposal after we discussed an initial plan, I usually will bring a spec sheet for all the key parts of the system, drawings, and other more technical documents.
In the past I have brought demo type materials like HDMI cables that are cut to show the conductors or amplifiers with the top off, but quickly learned that those types of items don’t really matter to the client. What they care about most is what it means to their lifestyle and how they will work it, not how it works.