Here is such an easy look to do for halloween. using mostly makeup items you'll have at home you'll just need fake blood and face paint.
Theres also a full tutorial to see it in action.
First apply a primer to your face as you need to protect your face and will also help the look last.
Then with your white face paint apply this all over your face making sure to apply it to your ears neck and also to the outfit you are wearing.
You then need to set it with powder to stop any creasing.
With a matte grey brown shade you need to contour your face. First apply this to the hallows of your cheeks, nose, jawline and hairline.
Then you need to go in with a grey shade and do the same thing to give you that dead look.
Just keep building and blending until you are happy with this.
Then with the same brown shade you need to apply this to the crease of your eye as a transition. Then with a dark plum shade apply this to the crease also but more into the crease to deepen up the crease. Finally with a black shade apply this to the lid and then blend this out into the crease to give that smokey look.
Then using a intense purple shade (I used a liquid lipstick as found it gave of the best look) apply this to the lower lash line and blend this out.
With a black gel liner apply this in the waterline.
Then you are going to want to fill in your brows. This can be to as dramatic or as you would normally do so.
Then with a dark red plum liquid lipstick apply this to your lips and then with a little bit of black shadow apply this to the centre of the lips to give that dead look.
Then with some fake blood apply this to your eyes to give the look you are crying blood. Add as mush as you prefer but be careful to not go over the top.
Finally apply some mascara and lashes to finish of the look.