Used a method that is close to the way I did portraits with Prismacolor pencils. Read a tutorial were the author was all about using a brush (regular round, solid brush) and the eyedropper tool (when blending) instead of "Smudging" or "Blurring". I set my brushes "flow" to 100 select my base color or value and create the shape of the face and neck, then turn the flow down to 1 and start adding shades. Sampling from what you've already colored (instead of snagging another color from the swatch) helps to make the blends smoother.
I did the last portrait "EmmaPeel_Redo" this way. Gotta say I'm diggin it, but with the two of these I did straight color, I didn't do a value painting first then add color... probably should have. Not 100% happy with the hair, that's something I need to just keep practicing on.