Try to reach that the dimensions of the arms and legs to be equal.
Now out silhouette is done now. I will choose my custom Brush number 47; it has angle and size jitter set to pen pressure, and paint some details, this brush is very good to paint feathers or something like this.
And now some face other details. Select #95 and do some amazing cloth pattern.
And face details with basic 1 or 2 px brush.
Here you can see that I've created a top gradient layer. Then I've just erased the gradient using my unique samples.
So we are done with this illustration. Practice your anatomy even if it bores you.