Head to the nearest Halloween store and look for the makeup and face paint. You can buy kits designed especially to help you make a clown face, or you can buy each color you'd like to use separately. Just be sure that the paint you purchase includes a good supply of white as white is the color you will use the most.
Practice your technique and make any necessary changes in your application beforehand so that when the big day comes you'll be ready to put your best clown face forward. It is also a good idea to test the paint. If your skin is prone to breakouts and allergic reactions, trying a small amount of the paint on a small section of your skin to check for reactions can save you a lot of misery later on.
Wash and thoroughly dry your face before applying the paint.
Start by covering your face in white paint. Clown paint is not applied right to the hairline the way regular makeup such as foundation is applied. Rather, make a large circle of white on your face that goes close to but not touching your hairline, ears, chin and jaw.
Exaggerate your mouth by making a black outline all the way around the mouth, following the natural contours of a smile but making the outline larger than your real smile. Carefully fill in the area inside of the black line with red. Include your lips as you apply the red paint. The finished look will create the impression of a very large red smile.
Apply a circle of red to each cheek. These circles can be at the center of your cheeks or attached to the corners of your smile.
Use the color of your choice to make large diamonds over each eye. The tip of the diamond will go about as high as your eyebrow and the same distance below your eye. The left and right sides of the diamond should extend just beyond the corners of your eye.
Use black paint to make several exaggerated eye lashes at the top and bottom of both eyes.
Your nose remain as it is, covered only with white paint. If you prefer, you could also cover it with a red clown nose--these are usually available along with the clown paint.