Shields:
I started from a black undercoat, and then painted the yellow sections of the shield with several thin coats of Vomit Brown, in order to end up with a smooth final result. Be patient with this, so that it ends up as smooth as possible. Painting 10 or so at a time is good, because the first layer is dry by the time you get to the 10th miniature, and you can apply the second thin coat of VB, followed by the third, etc...
Then Golden Yellow was thinned down, about 50/50 with water, and painted onto the edges of the sections. Since yellow is very transparent there is still some of the basecoat showing through. Once that dried, I highlighted again with golden yellow, the stroke being slightly less wide.
Next I painted on some slightly thinned Sunburst Yellow on the edges. Finally, Skull White was mixed in with the Sunburst Yellow and painted on the top edges of the sections.
I then took some Chaos Black and touched up the areas that were to be green, making sure lines were crisp. Then I painted the black areas with Dark Angels Green, making sure to leave a very thin black line between the segments.
I have a spare mixing pot filled with 50/50 Dark Angels Green and Snot Green. This was used on the edges, painted in a broad line. Snot Green was used on it\'s own next. Finally, thinned Scorpion Green was very sparingly used on the top edges of the green sections.
I took some thinned Chaos Black and touched up the line between the sections.
Hope this helps!
-Matt