I wasn’t sure whether to put this here or in “Tips & Tricks”…
I’m not sure if anyone had run across this before, but there’s a nice little website out of the UK that has free templates for making your own lens hoods (both regular and petals).
They have custom templates for various Canon, Nikon, etc lenses, including all of mine except for the fisheye (which has it’s own nonremovable hood).
While they’re designed for paper, I’ll probably pick up some more craft foam (I use it for making bounce cards) and give that a shot.
http://www.lenshoods.co.uk/