2009 is the best and the hottest!
Well i note some Gradual Changes.
Arms got skinier, Legs got bigger and larger, boobs got big and droping, ears got squared, shoulders got small, butt gone big, towel got larger, bigger eyes, larger scar, eye brows went down, and girl got skinier.
for those who don't know waht a gradual Change is... well in this pic things got diferent on the 2nd one from the 1st one, and they keep changing the same way on the 3rd one.
I like the 2005 one.
I like these comparisons of an artists progress!
The first is quite good, the second is great an the third is... amazing O_O
Breathtaking. (SPOILER, It's long.My badz)
There's a lot going on here as time's progressed. Your 2000 work was really smooth for line art, and it's hard to do that when considering angles and proportions for a body. The detailing there was simple, yet effective for it's time of completion(?)
Whereas looking at the 2k5 version, you've begun to experiment with coloring, and the way it's done seems to blend regular coloring and CG quite well. Not overly shiny, it's got a real absorbing tone. Similar to real flesh and blood people in a neutrally lit environment. Love it. Your detailing also ramps up quite a notch from the previous model five years before. While less attention is paid to strand count in the hair, it's easily disregarded due to sheer volume and styling of the hair itself. It actually can be 'felt' as if it had natural bounce and volume, rather than a bit of excessive hair gel in the previous version (Sorry, the hair just sticking out like knives irks me a bit...)
Moving to the '09. Last, but certainly not least sums this up quite well so far. Detail work has yet again changed with improvements and careful consideration to how it would affect her appearance. More earth tones were used in bringing out the natural beauty of not only the towel (which was amazingly done), but her skin tone and hair in general. Also of worthy mention, is your work with lighting has significantly improved, as shadows add a realistic sense of placement.. (perhaps being inside a white room with a large, single pane window?)
The shine levels have been adjusted a bit, to where she doesn't look like she's got a thin sheet of sweat or water covering her, instead it produces an incredibly attractive glow in just the right places. Her hair also has a slight bit of shine, but it only helps to bring out the level of detail involved (regardless of her hair in an extremely effective simple style).
With some final notes of mention being the creative use of lines and pigmentation (for the folds of the towel/cloth and the blush below her eyes, which are also nicely done...), I think you are definitely well on the way to finding yourself a version of Sonia that not only everyone else will already love (and be heavily anticipating) but also you yourself will be content with.
Truly congrats. I gave up my drawing in order to pursue writing and give creative tips, but I can't really find anything truly negative here to critique you on. Holy crow, I just literally wrote an essay on your work... I feel embarrassed now. If you ever need some writing done for your characters, I'd love to lend a helping hand. 5's and 10's where deserved (Which you do...)