Wear tattered cloths. Black nail polish on finger nails. Black lipstick. Paint face white and tinge a tiny bit blue for that decayed look and create hollow cheeks and eye sockets for the cadaverous look. Also you can get prosetic open wounds that can look real narly.
Just get normal clothes and get them real dirty. The best thing would be to go to a thrift stor and find your clothes there, they are old and out dated most of the time whitch is what you want. As far as the makeup here is a tut. YouTube - Zombies Halloween How-to Make-Up : BFX
There are a wide range of options with zombies - freshly dead, a week or two old, fairly corrupted, and near skeletal.
Embalmed? Looks just like you do now, with a more pinkish tinge to the skin, a darker lipstick than your normal lips and a visible blush on the cheeks.
The rest assume no embalming...
Freshly dead may sound the easiest, but it can be a challenge. You really have to know what human flesh looks like at the various stages to get the look right, otherwise you risk looking cartoonish. The newly deceased are a pale flesh color, sallow, like skin under a thin film of candlewax. Darker complexions "gray out", becoming ashen versions of the same shade of color, not actually gray. Livor mortis, or lividity, is usually visible, a pooling of the blood near the surface on the section of the body that has been lowest after death, usually the side or the back (note-lividity does not occur where the body was compressed or in hard contact with the ground, the bed, etc., because the capillaries have been compressed. Therefore, while the small of the back and the rear of the neck will be wine-colored, the shoulder blades and the buttocks will be the same as the rest of the flesh.) Lividity looks like massive bruising, a burgundy color that deepens to a maroon in certain spots. It is almost always visible on the ears and the sides of the neck, yet no one seems to do it when attempting zombie makeup.
The eyes are only slighty sunken, like someone deprived of sleep. Wounds will not be bloody, but encrusted with clotted blood, either blackish chunks or brownish smears.
The most successful detail to achieve this look? Learn the basic pathways of the veins in the face and neck and arms, then trace them with blue eyeliner pencil on the edges of lividity, i.e., the sides of the neck and trailing in from the ears and the temples. Get Ben Nyes "Death Wheel" palette and powder to set for the best selection of realistic shades for death.
After a week to ten days, depending on temperature, the body either bloats (few zombie makeup rigs deal with this) or begins to show signs of skin slip. This is when the eyes really sink and the eyesocket, the temples and the interior jawline become pronounced. Lividity will darken into purplish bruises edged in pink and sunken facial features with show this shade lightly as well. A green color begins to appear in splotches, first on the lower stomach, then shoulders, legs, torso and neck. Some sections of the skin loosen and form large blisters filled with liquid. The rest of the flesh will take on a yellow-gray color, very sickly. Sunken areas without lividity will turn brown and purple. Bacterial gases will swell the stomach and the lower face, so consider stuffing the cheeks and walking around with your tongue hanging out. You can either buy prosthetics for sunken eyes and raised nose ridges, or you can accent these features with makeup. Adding latex to the skin first and letting it dry in wrinkles is a good technique for this stage.
Soon, whole sections of the skin will darken into either a greasy black or a muddy brown. There will be stretch marks from the skin shifting due to interior bacterial gases pushing and swelling the flesh from the previous stage.
The eyes are gone, the nose has shriveled and the lips have deflated and pulled away from the teeth, giving the corpse a classic rictus grin. The shape of most of the underlying bone is visible. What flesh does not slough away becomes almost uniformly leather brown, like the mummies of Mexico. Under the skin, the fat has saponified, turning into a white, cheese-like substance, something to keep in mind if wounds are being considered. This exposed "cheese" soon turns into a yellow-orange like cheddar cheese.
Latex is the way to pull of this look, layers of it with toilet paper allowed to dry then torn and pulled to achieve a papery rot.
Finally, skeletal rot sets in, the revealing of the skeleton as dried pieces of tissue fall away or are consumed by insect and animal activity. The best way to achieve this is full facial prosthetics and skeletal gloves. Hard to be convincing unless you weigh 100 pounds and stand 6'2.
There are a couple of things that are considered "common knowledge" in zombie makeup that just aren't realistic, though you may find them fun to do anyway (I can be a bit of a purist).
One, fresh wet blood. Nope, blood clots real fast, so even a new zombie would be caked in brownish smears.
Two, zombie wounds are bloody. No, there's no bleeding, but skin fat would be visible, layers of corn-yellow pods of fat. Oatmeal, latex and makeup could give you this seriously disturbing look.
Three, zombie eyes are sunken. Well, yeah, to a degree, but lathering on circles of gray, purple or black around the eyes isn't the look. Darken the space between the eye and the nose the most, then follow and darken the lines of the eyelids, the eyeball and the socket lightly.
Four, exposed bone is white. Possible, especially with a post-mortem wound, but unlikely. Clean bone is tan, or white speckled with brown and gray, bone with marrow in it a light brown, bone exposed while the vicitim was alive looks like old wood spattered in older blood.
And no matter what you do, if you use makeup, don't be one of these people that does great work on their face and looks like a mask floating around on a healthy body.
Cover the ears, the entire neck, as much of the hands as you can manage. If you want a covering that doesn't smear, consider either alcohol activated makeups, or pax paint. Both of these are fantastic but will need a remover to clean them off.
If not, use Ben Nyes Death Wheel, or his Monster Wheel, or both, like me. Set them with powder and start stumbling around.
I shop here for all the products I've mentioned...(this link takes you straight to the Ben Nye wheels, but the menu on the side can lead you to latex, powders, all sorts of stuff.)
Hope this helps. I spent a lot of time playing around with cheap greasepaints and kits before I finally sat down and figured out what real quality makeup was and what could be done with it.
As to my comments on the stages of decay, let's just say I've had some interesting jobs.
I've got just a few helpful hints. Spats comment is a very good one and there's not much he didn't cover.
When I do zombie makeup, I do not use green. I use a color called Desert Sand, it's sort of a khaki color. Do not cake it on, rub it moderately over more pinkish areas of the face. It really does look horrid on skin. Make sure to get all over, especially cheeks and chest.
I usually add gray to the ears and the nose, since they're farthest out from the head.
I usually pour black acrylic paint under my nails and smear it over my hands. It stays on palms and fingers better than makeup and it washes right off.
I also sometimes line the inner rim of my eyes with red eyeliner. It's very subtle, but gross and looks horribly 'not right'.
And last, but not least, for the best looking blood splatter! It's going to sound gross, but it'll probably strengthen your friendship. Find a friend to fill their mouth with fake blood and spit it on you. Usually a mouth full of blood is good for two spits.
This was from last weekend, but we didn't really have much warning, so the clothes and makeup were not very in depth.
For an easy Zombie makeup, all you need is a simple Halloween makeup kit with green, yellow, red, black, and white. Focus on the hallows of the eyes and under the cheek bones when shading. For something a little more complicated, start with a stick-on appliance kit for a wound and then add the rest of the makeup.
For an extended description check out makefacebeauty dot com.