Highlighting isn't necessary if you're doing an army- but it helps your minis pop out a bit. Here I've highlighted the bow markings. Note, I've gone with one step of red directly onto our mid-brown on the bow; red is a bold enough color on its own an shouldn't need any more highlighting in my opinion. I have drybrushed the quiver with a gray two steps higher than the base gray, as well as the flights (feathers) on the arrows. I have also added another step to the leggings.