When you are showing something to a customer on your laptop, always ask the customer if the viewing angle is good for them. When you are making a presentation that is open ended, allow the presentees to dictate when they have had enough so they don't feel like you are rushing them. When your customer's corporate engineering representative stops you in the hall on your way to go get a nap before you come back to see the night shift operators, make it clear that you were seeking them out.
The customer bought you your lifestyle. Treat them as if that is important to you.