I don't have any pics on hand, but my advice to you is to not go overboard when you're modifying your costume. A lot of people tear their uniforms to shreds before completely coating it in fake blood. What it ends up looking like is a cheerleader that fell down a hill. For a decent zombie look, I would suggest focusing the attention on one shoulder. (I know my zombie movies lol) and once you get bit by a zombie, you'll turn in to one. So for the costume: If you tear a hole in one shoulder, you can use makeup or even inexpensive 'bite marks' from a halloween shop to make it look like you were bitten there, you can even poke little holes instead to make it look like the teeth. After the bite mark is defined, next put blood around the mark and on the front and back to make it look like it was dripping down the uniform.
You have to have a lot of zombie makeup on your face arms, and neck for this look. You can add additional tears, blood and dirt to the uniform to get it how you like. My suggestion is to let the fake blood dry overnight before adding more so you have a better idea of how it will look. I've done a lot of zombie modifications in the past, so if you have any other questions feel free to ask.
