And here's another important point: make sure your menu is readable from the back of the line. People don't want to shuffle forward and then stare at the menu while the barista waits. They want to have their decision made before they get to the counter. So the menu needs to be visible and legible.
I learned this lesson after I changed my menu board to a blackboard with chalk, written in a fancy cursive font. It looked beautiful. It was impossible to read from more than three feet away. The line slowed down. People were craning their necks. It was chaos. I changed it back to a large print menu with a simple font. The line speed doubled.
And here's something else I learned: don't put too many options. The paradox of choice is real. When people have too many choices, they get overwhelmed and choose nothing. Limit your menu. Ten coffee drinks. Five teas. Five food items. That's enough. More than that, and you're just confusing people and slowing down your service.