In this article I'll show you how to make the realistic scars on your photo like in the pic.1. Do you like it? Let's begin.
Open your picture and create a new layer (name it "The scar"). Choose Pen Tool and draw the line like in the pic.2.
Choose Eraser Tool and make following:
Set any red colour (I used #8C0202) and choose Brush Tool (set Mode: Color, Opacity: 100% in parameters). Then press Ctrl + left button of the mouse on the layer "the scar".
Apply Layer > Layer Style > Outer Glow and make the following requirements:
for getting "volume":
Choose Brush Tool again ( set Mode: Color Burn, Opacity: 10%, with the size 1 pixel) for making the scar with hems:
And that's it.