You can purchase these materials at most costume shops. In Philadelphia we recommend the official stops for all your Philly Zombie Crawl make-up needs Crash Bang Boom and Masquerade. You may also want to check out Pierre's Costumes. Or you can follow the "recipe" links and make the materials yourself.
how to apply your makeup
Step One -
Apply Molding Wax to form wounds and scars (Fake Scabs and/or Fake Flesh may be used as a substituted). Adhere these using liquid latex (Fake Scabs can be used as a substituted). Allow to dry.
Step Two -
Apply a base makeup color. Grey works great for zombies that rose from the grave. If you were recently turned into a zombie use a lighter tone that is similar to your skin color. Maybe add some green or yellow.
Step Three -
Apply accent colors. Use dark grey or black for places that need to be shadowed. Use light grey or white for places that need to be highlighted. A good way to do this is to shine a flashlight just above your face; shadow the shadows and highlight the highlights. Use white to also simulate exposed skull, red for blood, yellow and green for puss oozing wounds.
Mix and apply liberally. Be sure to bring extra to apply throughout the crawl!
Fake Scab Recipe:
1 part Gelatin
1 part water
Mix in small quantities and apply to skin within 30 seconds. This will harden to form a decaying flesh texture.
Do this before putting makeup on!
Fake Flesh Recipe:
2 cups Self-Raising Flour
1 cup Salt
4 teaspoons cream of tartar
2 cups water
2 Tablespoons cooking oil
First boil the water and add everything but the flour. Then add the flour slowly over a low heat. Cook until it becomes a warm doughy ball. Form this into rotting flesh slabs and adhere them to your face with liquid latex (ideally) or fake scab mix.
step-by-step techniques to zombiefy yourself from other sources