To help my crews, I've installed shelves (for want of a better name) like this around my layout:
My shelves were made by gluing a 10mm strip of 3mm MDF board along the bottom edge of a 35mm strip of 3mm MDF. They were then painted and attached to the fascia using double-sided tape. You can get a better idea of how they're made from this next photo:
I contemplate that when a train arrives at a town to do some switching, the crew will place the car-cards for the cars to be switched out, or perhaps those to be collected, in the shelf nearest to the industry. Whatever works for the individual operators is fine with me.
My shelves haven't been tested in an operating session yet, but John F. has made some as well, and says that they worked out very well, and he received favourable comments from the operators at his last session (which I was unable to attend).
Thanks for looking.