Research - Horror Make-up

For our killer we would like to give him a scar as it would show a convention of traditional hirror killers, they either have a mask of disfigurment on their face, I have looked at a few tutorial on youtube looking a horror make-up that we will be able to do under a budget.
As well as scars, I have also looked at other make-up such as cuts, open wounds and strangle marks.