Re: smoother shading techniques
Curved BugPin Magnums, 9's, 13's or 17's.
Set your machine to run at a lower voltage, ie: 3v-5v
I run a large gap between my contact point on both liner and shader.
I run my shader just high enough to push my hand against the A-Bar and slightly slow the machine down, any faster and your blends wont be as smooth and you can chew up the skin.
Use your rinse cup alot, a slight dip into water when transitioning tones or fades can help smoothen them out and blend together.
Dont be scared to go back over the areas if darker is needed, use black and white with your base colors for deeper or lighter tones.