Although the new parameter editor in Freestyle is starting to take off, I decided to revisit the earlier days when Blender just had the style modules. I rummaged through some of old test I did in Freestyle where I played around with the python code of the pre existing style modules to create new 'styles'.
It was pretty easy. All I had to do was mix n match, taking out a line code for a style module and replacing it with another line of code from another style module.
For more info see Metalix tutorial @ http://www.metalix.co.nz/tutorials/blender/other/freestyle/create_module.php