Draw in pencil on bristol board or another heavyweight type drawing paper that can sustain the wetness created from the marker. The marker will likely bleed through normal typing paper, but this usually does not affect the drawing side, so lighter weight paper can be used if that is all that is available.
Figure out a base color to represent the basic hue of your drawing. In the case of flesh tones, for example, this will be something light in the flesh tone range of colors. Lay down a solid layer of this color and then apply other colors on top to blend and create a skin tone. You can also apply more layers of the same color over the first to create shadows. Apply the base color.
Decide on the colors you will need to place on top of the base color to create the overall color after blending. Apply these colors. Continue to add colors as needed, blending them to create the colors you want. Single colors can also be used without any blending. The markers come in every color imaginable.