I would make sure there are adequately deep drawers and closets for vestments, a vault, a sacrarium, a niche with a kneeler with the before and after Mass prayer charts, and a “lavabo” sink for the washing of hands before and after Mass.
Speaking of washing of hands, a priest wrote to me asking help.
Dear Father Z,
We were thinking of getting the ante and post Missam towel racks, or having them made. The only thing I could find was this reference to a 1936 Patent: HERE
I thought maybe your readers might know of a place that still makes them or sells them. In the alternative, you might consider asking people to send in pictures of their own if they still have them in their sacristies.
I think this would be a useful resource.
A priest sent this in. Thanks Father GL!