You get two sets of images from yours truly, because I'm feeling like some teal deer today.

So, first, proportions!
1) Scout is lean and mean. Faces in general are no more than five eye-lengths wide, and then Scout has a hatchet chin that could probably kill if he headbutted someone with it.
2) His mouth is too wide. At the widest, the mouth only as wide as the irises of the eyes when facing forward. Smiles are also much more in the eyes than the mouth anyway, so if you want to have him be his usual cocksure self he should be looking straight at the camera as if to say "you want somma dis?"
3) The proportions of the earpiece seems off. I didn't fire up Source SDK to check, but a quick look at Scout's headset has it going from the bottom of his nose to well over his eyebrow, and the orange part isn't that big.
4) The collar of Scout's shirt should sit higher, having a "lip" that suggests it goes all the way around his neck. The slope of his shoulders should also be more pronounced.

This was done rather sloppily on another layer set to the Overlay blend mode at 75% opacity, and you're free to do whatever, but here are the suggestions I have for shading.

1) Have one well-defined main light source. I tend to default to upper right because I'm rather lazy like that.
2) Then, have a secondary bounce/ambient light source. This adds a rim highlight to the "dark" side of the Scout's face and better defines the volume thereof.
3) Speaking of, even though you're drawing in 2D, keep in mind the 3D shape of Scout's face. Faces are not flat: the forehead is shaped to wick sweat away from the eyes, the cheekbones are sloped to reflect light rays into the eyes (hence why football players wear eyeblack), the teeth give the mouth its unique shape...
4) Dudes have lips, too! I tried to pick a shade that doesn't look like makeup.
5) Teeth are not a single strip of white. Scout in particular has big buck teeth that add to his character. And, like everybody else in TF2, he has a rather pronounced underbite. Drawing the individual teeth also proves my earlier point about his smile being too wide--most people only show between 8-12 teeth when smiling (upper + lower fronts and canines).
6) Shirts, unless they're super starched, are not an unmoving mass. They'll wrinkle and pinch based on the forces pulling on them. I kind of half-assed this one, so I suggest you consult more references (or just use yourself as a model) to get a better feel for how shirts work.

Thanks for the tips. He's a sketch, though. Not really trying to go for true-to-life on this one. The subtle shading in mine shows that the faint light source is also from the right, as evident from the shadow of his nose and neck. Also, the lighter shading on his cheekbones is what indicates the 3D shape of his face, as you mentioned. I could make it more pronounced, though. The forehead could be a little darker, yes. I'll fix that. And yes, you're right about his headset. It needs to be bigger. So I'll fix that too. I like what you did to his shirt but the teeth and the shading on his face make him look kinda scary and sunburnt, sorry! LOL And actually, I dont know why everyone says Scout has buck teeth because he doesn't look like it to me. He just has a super wide grin, in my opinion. Basically, my sketch was based off the design that he is, in fact, a video game character and not a real person. But thank you for taking the time to critique it. I'll fix it up.

Ok took your advice and fixed some things. Added more pronounced shadowing on his face and shortened the width of his smile. Also made his headset a bit wider. The color around his lips was darkened but only slightly as anything darker made him look like he was wearing lipstick. I am keeping the teeth the way they are as, even though they are just a plain strip of white, adding teeth wasn't really consistent with the cartoony feel of the drawing and just looked...awkward.

As for the shirt, your shadowing is WAYYY better than mine but I tried. I'll have to keep dicking around with it. Valve seems to have 2 different styles of Scout's shirt; one being the non-lipped version we see in game, and a lipped version which hangs more like a regular t-shirt in promo pics. Not sure which one to go with....

Also, I must say that shortening the width of his mouth took away some of the impish-ness nature of his expression. :-/

When you say the mouth should only be as wide as the irises of the eyes, do you mean the from top to bottom or from one end to the other. Because in many pictures of Scout grinning, the ends of his mouth actually go as wide as the ends of his eyes.

>>6651
that rule only applies to an expressionless face from the front. grinning makes the mouth look wider, so does opening your mouth to yell angrily, and sometimes frowning does as well. it all depends on the expression. use a mirror as reference

>>6651
here's some nice reference i found. http://eyecager.tumblr.com/post/31600966403/basic-drawing-expressions-source-iain-mc-caig

That is an awesome reference. Thank you!! I'll be using that from now on. :)

Oops, my bad! I was remembering for the expressionless face.

But my original comment about smiles mostly being in the eyes still holds. Scout's eyes are in a neutral-ish position, which is why his expression looks insincere. (Consult your screencap to see what I mean.)

As far as shading goes, feel free to experiment with Photoshop's other blend modes--if you are going to use Photoshop, might as well take advantage of all of its tools.

Otherwise, I suggest you try Painter Classic. It's a program that mimics real media. It obviously doesn't have as many photo-manipulation tools, but it still supports layers, blend modes, and a few other goodies.

He's just lost in thought, that's all. :) Subtle fixes, not even sure if noticeable or even improved. Thanks for all your help!

Have to say, it's been pretty cool to see the development of this picture over time!