I'm not really sure what you are trying to accomplish or what it started as. Post a before and after like Likwid suggested so I can see exactly what your trying to do here.
Here’s how: First create a new layer. Then take a soft edged brush, lower the flow to about 3, and eye drop the color of the target area (in that particular section) you are to airbrush. Next, start brushing in either a half-circular motion or in the direction of the subject or area of execution. Make sure you continuously eye drop the same color of the intended area of airbrush. This will produce a clean airbrush rather than a one-toned color application over the subject.
Extra: Also airbrush in the natural direction on the subject...go with the grain, not against.
I been experimenting with the digital airbrushing too, tryin to get that Miami Kaos/EZ Soulja look. I dont paint over photos though, I draw mine out first then try to airbrush it like that.
i cant find that outline right now,but i followed a tut on digital painting and heres my outcome..Not alot of difference but some improvment..Only thing bad i see is its kind of blurry.....
I don't think that's a great photo for what you're trying to achieve because there isn't much definition or detail. I'll see if I can post some for you to mess with.