For stab wounds:
Special effect skin - I suggest going somewhere more advanced than a regular super market for this, just for quality purposes, and it will be available in more tones
Green, blue, and black eye shadow
When applying the skin, try to roll the skin into a tube and then smooth down the sides, keeping the center raised. Try to make the sides as smooth as possible, but they don't have to be perfect (they'll be covered with bruising color anyhow). To create the incision, take a smooth object like a metal spatula, a fork, or a toothpick and (being careful not to hurt your victim) run down the center of the skin. To keep a fresh, fleshy look, allow the skin to stay looking serrated and sharp, but for an older, deeper look open the incision by smoothing it back slightly in the same direction you smoothed the skin to attach it to the victim.
To stay realistic, keep in mind where bones are in the chest and what the size of the weapon is. As you can see, deeper wounds run parallel with the ribs.
For deeper wounds, add dark red or black coloring to the skin before adding blood.
For blood in stab wounds:
Corn syrup and water mixture
Red, black, and brown coloring - food coloring will work fine
For face make up:
Black and blue eye shadow
White or very pale foundation - depends on skin tone
Concealer - color depends on your skin tone
Most of the coloration can be done according to your own taste, but for face make up in particular, don't forget to put extra dark color below the cheeks and in the hallows of the neck for a more deathly look.