I first painted it all Mecharite red and then used the following picture from the 3rd edition BA supplement as my reference. I drew on the major components roughly using a mechanical pencil.
Once I drew on what I needed, I painted a black field and put dehneb stone down where their would be skin, cloth and white and iyaden yellow down were there would be yellow. I then began adding the details, starting with his lower body and working my way out.
I know some details are a little different. Such as what is below the scroll at the bottom. Really, this had to change because of the nature of the plastic space marine banner that I used.
Another aspect that is different is the blue sash across his midriff. I chose blue rather than green to tie it in with the rest of my army, where I heavily use blue.