So this is more or less an new technique for me, building out shapes with color, and then going in to detail. It's a very common technique, but I'm much more of a drawing artist than a painting artist, in that I draw everything out first, then paint it, and add extra details as I go. For this experiment, I chose a subject that isn't a straight concept, (that's next!) but something established, to help keep me honest as I focus on the techniques. I really enjoyed the looseness of the Fishman image, so I wanted to approach something like that again, and not rely on selections and paths to help out.
1) So of course I start out drawing the Predator, on its own layer. After all, I am an old dog. But I just really roughed it out - since it's an existing character, the shape is defined already, so I made sure to get the correct details, before I abandoning the drawing for the color block-ins.
2) On a layer underneath the drawing, I start with the color fill. I just blocked in the main colors, only a few for the core colors, and a few more to define the highlights - the black drawing defines the shading.
3) Now I begin to block in the tertiary colors, using the pick tool to help blend the colors, using a smaller version of the brush, with around a 20%-40% opacity.
4) I merge the two layers to a single layer (leaving the background layer white) and I begin to add in and accentuate the details, going around the image, sharing color picks to maintain cohesiveness. As I add in the detail into the focal points (in this case, I'm concentrating on the head, secondarily the rest of the body, and even less along the arm and fist) I'm still using the same opacity range, but the brush is getting smaller and smaller. Also, I switch to a hard edge point brush for finer detailing on the gauntlet details, and other spots here and there; chest armor, hair bands, neck piece, etc.
5) Here I do a quick color adjustment, a little brightness/contrast, and a soft edge airbrush to help blend color edges, at around 10% opacity. I then go back in with the detailing, decreasing the size of the brush, and increasing the brush opacity, to get tighter and tighter details. I also use the smudge tool a bit, to help redefine edges around the hair and metal pieces. Use the smudge tool sparingly - it's really easy to turn your image to mush - it's always better to use the brush, and pick colors to define and blend elements.
6) Here's the last relatively rough detail pass, getting tighter and tighter with the elements and indications.
7) Now on to the final detail pass, making sure I'm happy how the Predator is reading, and adding final details like the netting, and hot point highlights.
8) Final. After yet another fine detail pass, I make an adjustment on the values, and tweak the colors just a bit. I add a quick background, mostly color faded on top of a texture photo I had taken of a concrete wall. I wanted it to be really subtle, and make this mostly a graphic image featuring the Classic Predator. After I finalized the background, I move back to the Predator layer, and use the blur tool to soften the edges of the arm. Then I do just a couple of quick soft highlights - 10% opacity, white color, soft edge airbrush, to help tie together the figure and background just a little bit more.