I kind of made my own without realizing what I was doing or that this was even a thing. I had some extra Kleenex from his office box stashed in my pocket and somehow they became comforting for me. They've been in my pocket for several months now. They've even been on a cross country trip with me. I also did the same sort of thing when one day I filled up my water bottle from his office water cooler. Both of these things became a sort of physical connection to a safe place. He knows about both of these things, but it was super embarrassing to tell him about it. I think he was amused in a good way by the story I told him about the water.