I’m sure they are not the only ones, do you think they were? They did show how they could be done, though.
Besides, real crop circles were first documented in the 1800’s, long before Doug and Tom (I think that’s their names).
I’ve done a few UFO hoaxes, but not crop circles, and I’m not the only one who does them. Properly done, they are very amusing to read about in the newspaper.
I like the flares on helium balloons, those are good.