You can impress fine wood grain pattern into thin wood, paper or styrene with a wire brush. The trick is to lay the bristles almost parallel to the paper surface at just a slight angle. That way it does not tear the paper, instead it leaves track marks from dragging the wires at a low angle. But also another factor for making faux wood grain marks on wood and paper is dragging with the grain rather than across the grain. You will need to experiment with the amount of pressure and the size of the wire until you achieve something you like.
Stir sticks tend to be made from fairly hard wood so they don't achieve embossed grain as easily as basswood or cedar will. For timber framing in scale I always head for the tight grain red cedar. The image below shows cedar textured and modeled for the wall timbers at 1:12 scale but it also works for smaller scales if you get a hold of the really fine grain pieces. I find the best tight grain, old growth cedar, at Home Depot being sold as cedar railing spindles. You can saw one of those 1-1/4" square by 3 foot long pieces into a good sized stack of miniature lumber for under $2.00.
The floor boards in this image were made from thin, old growth Sitka spruce from Alaska. That is not something you can find at the lumber yard. I get it as offcuts from a sawmill that specializes in wood for luthiers. That other object on the floor is a soap stone sink I carved to be used in this project. I wanted a natural stone edge on the front of it.
