It's usually the last thing on your mind, but you have to be clear thinking all the way to the end.
When you are packing up to leave the floor, be sure and have all of your boxes, crates, skids, bags and cartons accounted for and assigned to an outbound shipment.
Make sure that there is a bill of lading (BOL) for each outbound shipment (depending on the hall and the general contractor, this may also include FedEx and package deliveries).
In the case of the recent show we produced, there was a local shipment. Be sure and be clear to the I&D crew, your show house contact, the driver and anybody else who needs to know--where and when does this package/shipment have to be where it is promised to go.
Then, and only then, can you leave the show floor. It's always a good idea, if you can, to be on the floor from move-in to move-out, to be there from bare concrete to bare concrete.