I think that Cavorting has some very fine suggestions and am now going to pick up on Zani's idea: When the planning is reasonably complete, consider a 'dry run' to your airport of departure.
Perhaps a friend can accompany you and just walk the check-in process from getting out of the car until people go through into the secure area. You would be able to see how people queue, how they get questioned (not at close quarters) and see the 'flow' and the stages that you will be expected to go through. You might get questioned by officials as you will be seen to be studying all that goes on!!!! Here again, the explanation of being a nervous passenger is the right one - and you would not be telling a lie!
It's not much, I know, but by looking at the stages that you CAN look at, then more of it will be familiar (if not comfortable) on the day itself.