First, place the tin of polish in a warm spot in the kitchen or near the furnace to soften it. This way, it will spread and penetrate easily. Next, use a soft cloth to apply the polish and work it into the wood. Finally, use another soft cloth to buff the wood to a shine.
Clear polish works with all woods. Lighter browns work well with walnut and similarly-colored wood, and darker polish works better with darker woods. The polish can even help fill in and/or hide minor scratches and nicks in the wood.