Hi there!
First chose the point the scar is supposed to be.Then chose the kind of the scar(for example,a deep scar,a scar that left a hole,a scar that left a line of additional flesh,a cured scar or a scar made a couple of hours ago or less etc.).
I'll describe how to make a scar,that,after it cured,left a line of additional flesh:
1)With your Number 000 Series 7 Winsor&Newton Miniature Brush(or any other brush you may use of this type...)draw a line to the point the scar should be.Use a dark flesh color tone,but not the darkest you have used for the face.Do not use redish colors in your mix.
2)Cover this line with a lighter tone of your mix,but not completely.You should cover the upper edge of your darker line and leave uncovered the lower edge.
3)Keep highlighting the upper edge,always leaving a very thin line of your previous color uncovered.Do not highlight more than you have highlighted the rest of the face.
4)Make a very thin mix of your basic flesh you have used for the face.1 part paint to 12 parts destilled water.Load a bigger brush(Number 0 for example...),unload it VERY VERY VERY well on a cloth and pass the brush over the whole face,but NOT the eyes!!!
That's it!If the scar has left a hole in the point instead of additional flesh,use the same technique,but do it twice,like two scars of the first type(the one I described...)one painted close to the other(not exactly like that,but I'm sure you'll find out what i mean if you try it...).Remember that if the scar passes over the eyeball,the eyeball should be white!
I hope you understood me(my english is very bad
).Any further questions or clarification are welcome
Good luck and let us see the result!
-Kostas.