* prepare list with separated categories of importance for followups - and write it down immediately after talk, so you do not loose a details

* if you do not have stand, try to share your location or communicate where you will be at what time ... via twitter?

* hydrate :)

Ask questions of people you meet. You’re a start up. By definition you are not an expert in your customer needs. Use the chance to ask contacts you meet for help (connections, advice, etc)