The key software tool for this sort of tweaking is an edit selection tool that 1)lets you click on a pixel and autoselect the adjacent region of pixels that are within X tolerance of that pixel's hue/brightness/whatever and 2)lets you make multiple selections and adds or subtracts each new selection from the current overall selection. This is useful for all sorts of effects, extracting an item out of its background, etc. Then, it's just a matter of practicing and (usually) learning when to quit fiddling. (For the other icons in the OP, I'd mostly just want to recrop them to 117 x 117; the Vinnie one might benefit from a bit of similar color-tweaking to bring out the detail against the dark jacket.)I'm now highly motivated to learn how to use my other software better.