Chose your texturing tools. Here I am using artisan-made stamps, in a nature theme.
Stamp both side of the washers.
Pro Tip: My stamps have a round shaft. Every time I moved to the next section or put the stamp down, I had to stop and look to see where the design was orientated. I added a dot of Sharpie marker to the base of the design I wanted facing me. This have me an instant visual of where the stamp was pointed and speeded up my process.