This is pretty cool coffee,
The only real problem with your execution of selout here is that it is the same throughout.
The main difference between this sprite, and kenneth's is the fact that you use black as the darkest selout shade along the entire piece. The problem with doing this is that it ignores whatever light source you've established, and serves to make your piece look like a cardboard cut-out. The main thing you can do here is change the selout shades, and make them progressively lighter or darker, dependant on the light source. I might do a demonstrative edit later, but I hope you can understand this in the mean time.