All I did for this Zombie Halloween costume was got some old normal clothes, put a few cuts in them, put some mud and fake blood on them. Then I covered my arms, neck and face with white face paint, put some black on my eyes and cheeks.
For the cuts I just did a line in black and red face paint then put fake blood on them, same for the bullet hole. Then back combed my hair and put on plenty of hairspray.
Altogether it only cost £2.00 for this look, that was for my face paint and fake blood.
Cheap and really easy and looks pretty good!