Two jobs happen at one counter: taking an order and handing one over. Setting it up so those two sides stop fighting each other is most of the work.
A pickup counter on a fairground is asked to do two things at once - take money for an order that has not been made yet, and hand over one that has. Both happen along the same stretch of trestle table, usually with the same two or three people behind it, and most of what goes wrong at a counter on a busy ground comes from those two jobs landing in the same spot at the same moment. The fix is rarely more staff. It is deciding, before the gates open, which end of the counter takes orders and which end hands them over, and making that obvious from a good way back.
Then look at where the whole counter stands. Face the order end towards the direction people arrive from, so the line forms along the front of the counter instead of across the path. Check what is behind you: power you are not sharing with a stage or a ride, somewhere dry for spare rolls and a spare printer, and a route for a crate to reach you without crossing the front. Shade matters too - a register and a printer both go unhappy in full sun, and thermal paper left in it prints grey.
The person who took the order and the person who hands it over are often not the same person, and by the middle of the day neither of them remembers it. The printed ticket is the only thing that does. Ring the order in at the register, let it print at the station that makes it, and keep that ticket with the order all the way to the shelf - in the bag, under the tray, clipped to the rail, whatever survives your counter. When a handover is questioned, the ticket settles it instead of two people rebuilding the order from memory.
That means the ticket also has to say which counter it belongs to. Give every counter the name that is painted on its sign, not one name on the ground and another in the system, and set each station to print its own orders and nothing else. A counter that receives one ticket meant for its neighbour will spend the rest of the day reading every ticket twice.
Set the counter up the day before if the ground allows it, and run three orders through it exactly as somebody arriving would: order at the order end, watch the ticket appear at the station, make the thing, put it on the shelf, hand it over. Do a fourth with something awkward - a modifier, a change of mind, an order that splits across two counters. Twenty minutes of that finds the extension lead that is a foot short, the printer nobody plugged in, the sign standing behind a pole, and the counter name that does not match what the system calls it.
Then write down how the counter was laid out and leave the sheet at the counter. Crews change between days and between events, and a counter that was set up well once drifts back to a single pile on the table unless whoever opens it next can see what the last crew decided.