A few pointers from my experience. Some of these mentioned before....
1) Try and demonstrate (or plan to) something that empathises with the audience's situation or market. People like to know that it's valuable in THEIR context.
2) No jargon, acronyms etc. Just because you know the latest buzz-words or TLAs, that doesn't mean that the viewer does.
3) Plan ahead. Make it simple (KISS principle) and produce a flow that not only covers the features, but does this in a logical way.
4) It's useful to have an agenda. If that's in print/PowerPoint/Prezi etc, then use that to show what you'll be showing and why. Then show them. Then circle back to the (1 slide) that summarises what you've shown them and seek agreement on what was achieved/valuable. This acts as an opportunity to seek agreement/close as well as uncovers any open questions or objections.
5) if possible, and dependant on the context, use multiple aids. Screen/Whiteboard/Visual prompts etc. A change of focus helps to break up lengthy discussions.
6) Seek feedback and ask open questions. Basics really.
7) And so on....
I used to run a course for my engineers to present the 'art' of presentation. We called it 'presentation skills training'. Not only was it well received by our tem, we also noted a significantly higher close rate, more engaged and satisfied audience, and more focused and incited tech team. (The latter did most of our demos).