nice work! but IMO many of your avatars are over exposed!
I mean your avy's look overbright to me. try using the contrast and brightness using adjustment layers. Also use gradient maps and color balance to achieve desired lights. As a finishing touch you could try using some lens flares.
i have a doubt what does the gradient map do........?
As far as I can tell, the Gradient Map takes the foreground color and background color, forms a smooth gradient, and maps it to the brightness levels of the image. While black and white works well
Well i would say that a gmap has the capability to do the combined effect of hue and saturation and the solid gradients. If used properly they can used to achieve great lights and add great depth and add more sense to your work IMO.