If I may post an example here, I want to show him how I did the Charmander revamp.
Ok, so here is how I did it:
I went and really overhauled it... If you notice, the bightest shades of the body are at the top left. I also redid the eyes, as they were not even close to DP style, and I made them have a sort of "cutesy-mad" effect. I also completely redid the flame on the tail, to make it more like the DP sprite. It isn't my best revamp in terms of shading, but I did it pretty quickly.