I anti alias as I go along with the shading Saimo, everyone has their own working method, but if you anti alias before you set colour, your anti alias will have incorrect values, and if you anti alias before you set shades, your anti alias may turn out too bright in dark areas, and if you anti alias before you set details, you may need to spend more time to get the details in. I myself do it before the fine details and texture, simply because I then get a better idea of how to put in the detail I want. That's just personal though.