Nice image although not sure about the light beams, looks like a night scene so confused as to where the lights would be coming from.
Good creation all the same
Thanks for the link Eggy - great and useful link. FWIW I agree that the rays would be better white, or at a push with a very (very) slight yellow tint.
I used a brush by the excellent Gavin Hoey but it was a bit of a shortcut - following the instructions in the video link you gave would certainly have produced better results.