In terms of stuff that has helped me I'd recommend the youtube channel, "MarkoValeKaz". He has a video called "Improving Readability."

Also check out and analyze the "Street Fighter Alpha Sprites". Alot of the three quarter view sprites remove/have less contrast for back leg to draw your eye to front leg more. 

Also, there is a video called, "Street Fighter Alpha: A Study of Character Stylization," by, "Brandon James Greer," on youtube. That video analyzes the Alpha Sprites I mentioned. 

And lastly there is a video called, "Why smaller pixel art is actually harder", by the youtube channel, "AdamCYounis." It has a section about 6 minutes in that discusses readability. Hope that helps.

Nice character portrait. I like the color palette and the final look. My critique would be experiment with more distinct outlines to squeeze more depth from the image; some of it is lost in certain spots. Like where the sash meets the hair, the hip overlaps the hair and the hand meets the thigh, I feel there could be more depth in those areas. Though, regardless it is still a good portait.