Wow! What an improvement! You've really improved in comparison to the other two. I like the coloring on this much better, and I think this style is more flattering because it's what you actually look like. What I mean is, it's a whole lot closer to your actual appearance than the other links you provided. I always take cartoon-ish self portraits with a grain of salt, since it's inevitable that some features will be stylised. The eyes in this picture, however, look a little flat. I'm not the best person to answer how to improve it - I don't consider myself educated enough or experienced enough to really identify exactly what needs improvement and how to go about doing so. Also, I personally think a little stronger highlighting on the glasses would make them seem more "glassy" and reflective. (yes, I use wonderfully technical terms XD). I love the dynamic shading! The touches of green on the cheek and chin really do a wonderful job of showing the light reflecting off your enviroment, which really shows how well thought out this piece is (ie you didn't slap on a BG last minute). I think it also shows a level of elegance and expertise since keeping that lighting in consideration is often neglected (I believe this mostly because I always forget it myself). Overall, a splendid improvement, and I think you've done a great job.
Thank you for the wonderful critique! It's so rare that people actually comment on my stuff O_O This was my first real digital painting done from life, so I think I got a little nervous and relied too much on what I saw rather than on what eyes and glass actually look like. I think figure painting should be a balance of knowledge and observation, and I kinda failed on the knowledge portion here xD I should really redo this piece..
Ahaha, no problem! It's the same for me, except probably even rarer since I'm sure you get more traffic than I do. But I think it's very important to rely on what you see! It's not necessarily always a good thing to throw in some knowledge if that knowledge doesn't suit the situation. Like, it would be a mistake to make your glasses super-shiny if the glasses being observed were actually dirty/in dim lighting/other factors that would decrease glossiness. In general, though, I definitely agree that knowledge + observation = ultimate powa in figure painting.
I think this piece is nice as it is - redoing it would be like beating a dead horse. Maybe doing another self-portrait to show improvement would be a good idea, like this one is in comparison to your previous ones?