Time to earn my bread.
Drawing a superdeformed muscle doll is not really the easiest thing to do, and you did a pretty good job at it, but there's a lot to squeeze into a very little space, and that's prolly the hardest thing there is to pixeling.
First, and you'll hear this from almost anyone here on Pixelation, think about the volumes. Imagine that whatever you are pixeling is made of simple and well defined shapes, then try to define those shapes well. Each of those should be clearly distinguishable.
Keep it simple, and dont get into any detail until you think the shapes are exactly what they should be. For example, you don't want the chest to look too round, like a woman's breast. They should look at least a bit angular and chiseled.
When you decide that your light is coming from, say, above, you should think about which surfaces catch that light, and which are in the shadow. Doing a 'glossy' shading with focused specular highlights is deceiving in this aspect. You may think that you got away cheap, but in the end you only fool yourself from seeing the mistakes. It's much better to do simple shading and define materials by adjusting the brightness and hue of their colors, instead of doing speculars, dither, etc.
Also, think about pixeling as painting, not as drawing. For instance, when defining abdomen, you did it by drawing darker lines and then placing almost-arbitrary highlights. Instead use light AND dark to get a much better result. Trust me, it's worth the sweat. If you get stuck, feel free to look how others solved similar problems. It's best to look at ppl with a very clear style, than those who work a lot on a sub-pixel level. For example it's easier to look at how kenneth solved something, than to look at how Helm solved the same thing. The latter style is more 'advanced' and much harder to read, so to speak.
Since a picture is worth more than a thousand words, here goes:
I didn't want to change your design too much, and it IS a rather half-assed attempt, but I tried to show you how much definition you can get out of those pixels. Pay attention to ears, hands, and other very small bits to see how they differ from your original work.
Also you will notice how much i exaggerated certain features. This is almost a must when working on tiny sprites and such.
Last but not least take a look at how I changed the colors. The changes are very subtle, but if you load your colors to my image, you'll see the big difference.
