To begin to make a weathered or shabby chic finish on your miniature foot stool, apply a grey stain to the wood before you paint it. You can use a weathering solution to age the wood or you can use a simple stain as I did here made from a dilute solution of Payne's Grey watercolor.
I applied the Payne's Grey solution to the surface with a stiff brush which helps to raise the grain of the wood. Allow the surface to dry, then sand it lightly, depending on how rough you want the wood to appear. The grey stain will show through as weathered wood when you sand the final painted surface of your miniature.