Simplest flies

I have a FlyFishing mag from England that talks about 'minimal flies', and
the most minimal successful fly it offers is a red circle hook. That's it!
They say it works really well, as it replicates a larva of something or
other that trout eat, and the author says he has had good success with it.
They say you can paint a circle hook red, or even simpler, just buy a red
hook.

The next minimal fly was a regular wetfly hook with a brass bead. That was
it! They said that it represented some other critter who rose to the surface
in a little air bubble, or possibly it looked to the fish like a piece of
roe. But the author said that both worked well to catch trout.

Anyone ever made serious use of 'minimalist' flies like these? Puts a whole
new spin on tying your own flies!

--riverman