Don't do this in a bedroom unless you want the room to smell like soy sauce. I didn't think about that until after this project.
Gather your supplies and set everything up.
Put some of the soy sauce into the bowl. The amount depends on the size of your wood.
Make sure that the piece of wood is clean, wipe it down before you start staining.
Start staining the wood. If the soy sauce has small holes, just put on more soy sauce and brush it in.
The stain won't be as dark as the soy sauce. When you're done brushing, let it dry. If you want the wood to be darker, let the first coat dry, then add another. Continue until you're satisfied.