It's casual. Just have your stuff organized and try to hand it to one of the pilot's (usually uniformed) at the booth. You'll get a minute or two to chat depending on if there is a line up, and that's about it. Of course talking to the BCP (if he is there) is best, but giving your stack of stuff to any of his minions will work.
If you show up to the FedEx hanger in a suit and tie, they will know that you're not a local. Don't bother with getting all gussied up for a minute or two of chit chat. It won't matter if you are in a suit, or in your Carhartts, you stuff will still end up in the pile to review.