How do you do all of the red texture stuff? I use SAI and I have frequently asked how people do backgrounds and textures, no one will answer me though. Do you download, or make your own textures? If you make them, how do you do so?
You can try downloading royalty free textures. Then open the texture on Sai. Make that layer's property into an Overlay. Then lower the opacity to what will suit your drawing. And yes, I sometimes download textures and sometimes I create my own.