I have just spent a session giving an extra layer to the jacket.  I have also added some finer detail near the edges of the jacket, close to the zipper.  The photographs tend to look better than the real thing in the early stages, but close up to the canvas the patchiness is more obvious.  I am constantly looking at the light and shade and, whilst I am not too worried about exact colour matching, I like to end up with colour combinations that enhance the painting.  I have mixed some white in my colours, a technique that can deaden the colours, but sometimes it is a necessary evil!