Practice with pressure. Pressing hard versus pressing lightly can have dramatically different effects, so you should get a feel for this ahead of time. Also, practice using different strokes to prepare yourself for tattooing different kinds of artwork.
Your hypothetical light source should always be the same throughout the course of your shading. You don’t want the shadow to be incongruous. If the top part of an arm is lit up, then the bottom part should be darker. If you’re using colors, try to shade with complementary colors. Grab a color wheel and find a complementary color to the one you used for lining. This will make the tattoo really pop.
Using a circular motion is gentler on the skin than going back and forth.
Remove any remaining ink when you’re finished with the tattoo as well.
As you apply the ink, tilt the needle in a circular manner to blend the tones of the tattoo effectively. This will apply a different amount of ink and contribute to the shading.
