I am pretty virulently anti-filler.

there really doesn't seem to be any method of determining "how much" to use (it's typically Dacron fiber, like you'd get at a fabric store).

terms like: "some", "a little", "not too much", "a tad", "a pinch", and "just enough" give me the willies when used in the context of reloading.

people do it though.