If you want to improve, you'll now have to go further and start adding a darker tone to the skin as well as a lighter tone, and a highlight on bump areas when you feel it's necessary. You can achieve some neat effects using this technique.
Here is an example of something I made some time ago, using 3 or 4 tones (+ gradient) in most areas :

Spoiler, click to toggle visibilty

http://img87.imageshack.us/img87/5223/didigradientxc3.png

the position is good (it reminds me of something but I can't put my finger on it), legs and  torso are good, but the face (and nose) looks a bit odd.

http://i158.photobucket.com/albums/t117/maximilianjenus/pad.gif

I have been working a project of my own with all the Street Fighter Games. (I'm not very good with the whole scripting and stuff) So I decided to collect all of the char and the stages and BG music. I have 56 chars in all ranging from SFII,SFA1,2,and 3 SFIII, SFIII 2nd Impact and SFIII 3rd Strike.(no duplicates) I only have Gouken from SFIV. I also have a few edited chars that fit that the style (Dyan Silva, Blaze Agent, and Tigre Negro)

Here a pic of My select screen



But if your looking for SFIV chars they are really hard to come by( I know I have been looking)this is the best I found http://forums.shoryuken.com/showthread.php?t=195149 the authors name is Steamboy33.

but the funds at it I am employed

this is not an edit this is what the club-syndicate screenpack used to look like before he changed it. he just brought this back as something different. as he said V3.2
EDIT: just look at older club-syndicate screenpack videos on youtube and you will see it. if im wrong then o well but im 95% sure im right.

- Syn for letting me edit his sp and lifebars.. and release it