Nice job on the tutorial, but I do it a different method. :shock:
Just a little different way of doing it:
Draw a white line with a 2-3 px Line/Curve tool using bezier curves over your render on a new layer.
Erase the parts that should go behind the render. This makes it look more natural, that the lines would actually connect around behind.
Taper out the ends to a point using either the eraser tool if it is curvy enough, or a transparency gradient if it is rather flat.
Gaussian blur by 1 px.
Use Outline Object at a 2-5 px radius and a softness of 253-255.
Run glow at default settings