Farryn

That's great! Keep up the good work. ;) I was terribly bored, studying for my exams here, so I went ahead and did a real quick 5mins touch up on the saturation and hue of your picture mainly. Hope you don't mind! ^^

Ahaha xD It's fine and I do see what you mean in regards to the thighs, the shading is too dark around there and should be a bit brighter and blended into the lighter colour. Thanks!

Yeah, but that's really easily done. I'm quite sure SAI has the dodge and burn tool. Google it for a moment. It pretty much increases the saturation and hue of the color you already placed. So rather than adding 'pure black' (RGB: 0.0.0) which gives you the feeling of 'sitting or laying' on top of your primary color. You're simply darkening the color.
Burning and Dodging is going to make your life 100 times easier. ;) Check it up on ytb or google, I'm sure you'll love it.