Using brush select any color that will going to be use for the base color of the lips. I selected darker color of red and brush on with 100% opacity. Then I use eraser tool to shape it into lips.
step 2 of 6
for the teeth and gums outline -
brush on in the middle color #f4eacf, followed by color #f4cfdb brush on the side to blend for the color of the gums.
Make an outline drawing for the teeth using color #a0516b.
I made the color combination only experimental. As long as you use combination of yellow pink/red and blend it by adjusting the opacity and fill. Brush on several times the pink color with small percentage of opacity let say 48% or less until you satisfied with the color combination.
step 3 of 6
Lips and gums shading
Lips - Cover the areas by using the same color of the base and overlapped with the gums/teeth to form the lips. Use darker color and
adjust opacity and apply on lips areas. Also apply randomly small dots. adjust size of the brush and opacity.
step 4 of 6
Glossy Lips and white teeth
step 5 of 6
Skin
step 6 of 6
Final touch -
I make the skin lighter by using airbrush and white color with 15% opacity. and apply as desired, add orange color lighter one on the lips and cheeks (face) opacity use 10%. Brush it to and fro.