Dark spots can be cover by chemical bleaching or by makeup. Chemical 
bleaching will frequently lighten the spot at least for the time being. Even if you make a decision to cover up dark spots with out chemical bleaching process, then we need some basic makeup products.
How to cover up dark spots on face by makeup
Wash your face with a mild cleanser and clean with a towel and apply a face moisturizer.
Apply a light makeup liquid base or foundation which is same shade as your skin color appears. Apply lightly the makeup onto your finger tips over the surface of the face.
Do not focus on the dark spots. Foundation is meant to level out the overall color of the skin. Mix together the makeup well.
Choose a neutralizing concealer based color on the main color of the dark spots. To cover the area sufficiently you may need more than one color.
Directly place the tip of a solid light-colored concealer stick on the spots and apply. Your skin tone or be slightly lighter this concealer should match on the dark spots.
Use your finger tip to mix the multiple colors of concealer together to cover the dark spot. Look at the spots in a mirror; if you can still see them, repeat the process until the dark spot disappears.
To set the makeup brush on loose facial powder which helps protect the concealer from rubbing off and revealing the dark spots!
