Choose the image of a zombie from your favorite movie, book or show and have you artist trace that image for a stencil. If you don't want to directly use a zombie's image, you can draw your own or simply instruct your artist to draw it for you. You can tattoo the complete body or just the bust line and head of a reanimated dead person, depending on how large you want the tattoo. The gory details of dripping blood and rotting flesh are entirely up to you.
The cross-section tattoo is a patch of skin tattooed to look like a different material. This patch can look like an animal's fur, a robotic circuit board, the spreading of venom from "Spiderman" or, in this case, the spreading of zombie skin. Consider tattooing teeth marks at the epicenter of this cross-section to imply a zombie bite as the point of origin and incorporate sickly greens and yellows to portray the rotting of your skin into that of a zombie.
Since zombies are notorious for seeking out and eating human brains, zombie fans with a more comedic flare may consider a nature in reverse tattoo of a brain eating a zombie. The design can be gruesome and graphic with a multitude of colors to display each detail or more reserved and done in traditional shades of black and gray. You or your artist will obviously need to use some artistic license, since most brains don't have teeth, but the message will be clear and comical to anyone who sees it.
A zombie script tattoo can be anything from a quote out of your favorite zombie movie to a word or phrase tattooed in a zombie-like font. For a quote, choose any script you like or design your own to give it a more personal feel. For a zombie font, the letters should appear like bones wrapped in a zombie flesh that is festering and falling of in some sections. The letters will have to be large and bulky to show the details, so a limited amount of words is advised.