Have a "mark printed" checkbox when printing packing slips
Of course, the functionality to have a "printed packing list" status or column would have to be implemented first, but the idea of knowing what orders you've picked picking or packing lists for would be ideal.
Currently, our customer service department prints orders out of our web store, and gives orders to our pickers/packers who then print from ShipStation. We would probably use the print pack list feature more easily if we had a way for ShipStation to mark the orders as having been printed, do avoid printing duplicate orders out of the system.
StickerTalk, LLC. commented
We also use the tag function for this, but an automated version would be fantastic. If you forget to mark the orders as printed, then you can't print again until you have shipped everything.
Nicholas Jensen Lifetime Creations commented
We also use the tag function. Create a tag named "printed" then when you print the order, tag it as printed.
Wil Tushaus Brown Dog Gadgets commented
We use tags to keep track of which orders have printed packing lists. When I select the batch to print the next thing I do is to click the "Tag" button and then "Packing Slip Printed."
If you have the tags column visible on the page you get a quick visual cue of what has and hasn't been printed.