Robbie wanted to be Jason Vorhees for Halloween, and this is what we came up with. I used this video to paint his mask. (be sure to view parts 1 and 2) The jacket came from Goodwill. I removed the buttons and replaced them with black ones. Then I ran over the jacket with my car making sure to turn the wheel repeatedly to really scuff it up on the ground.
That wasn't enough, so I used sandpaper and a foot file to weather it a bit more. It really doesn't show up as well in the photo though. I used red paint for the blood on the machete that was bought from Spirit Halloween. Total cost was less than $20.