We use a lot of letters and documents (actually in one of my previous campaigns I had two charactes who kept up series correspondence with some long distance NPCs -- picked up several handwriting fonts so it was easy to distinguish who was writing).
We also use washers for coinage and keep them in moneybags/purses. They can also get Letters of Hand/Credit so that they don't have to carry all the cash all the time. To that end we have also used some coloured markers for gems.
There are the various maps, of course, many of which are more of the "poetic" than topographical variety, in keeping with the era we are trying for, technologically speaking.
Miniatures when we feel like it, but that is very, very rare.
Some people have started bringing hands, wands, and bags of "stuff" ("spell components")to the table. And there is quite the fight over specific mugs in my cupboards (the skull mug is a particular prize, followed by a couple of hand-thrown, not by me, ceramic jobs). We also use some very old-fashioned style tarot cards for local card games (based on 16th century tarroc rules).
If I don't watch out, the group will show up in costume soon
