When my girlfriend dumped me I found hobbies to busy myself in... Sadly enough, making latex scars was one of them. I am not experienced in any way, this is how I do them, they don't look amazing but some of them turn out quite realistic.
Step 1: What You Will Need
1 Bottle of Liquid Latex (check on eBay for good prices)
A Syringe (optional) Used for a fine, controled flow of latex
Medium & extra fine paint brushes
Red, dark pink & light-medium brown paints
A piece of paper for a dry brush effect