With a dry or sensitive skin, you can apply Grimas Under Make-up Base. Allow 10 minutes for it to be absorbed before you continue.
In the case of combination skin, you could apply some Grimas Anti Shine to the greasy parts of the skin (nose, chin) before applying the make-up.

In this example we are working with a base of Grimas Camouflage Make-up. The optimum colour approaches as much as possible the colour of the own skin.

UNDER MAKE-UP BASE = Under Make-up Base
ANTI SHINE PRIMER = Anti Shine Primer
CAMOUFLAGE MAKE-UP PURE = Camouflage Make-up Pure
Take the Camouflage Make-up out with a clean spatula.
Rubbing it with your fingertip will make it softer and easier to handle. If desired, you can make the texture softer and affect the colour by blending the Camouflage make-up with Crème Make-up or Foundation, for instance.
Apply it with a slightly damp latex sponge or make-up sponge onto the skin. Work the base out properly, up into the hairline, and do not forget the ears and neck. This is how you avoid a mask-like effect.
A dark shadow under the eyes or other irregularities you neutralise with IV5.