It's easy!
Especially with teenagers, say, around age fifteen or so, who are just opening up to the mysterious powers of language and poetry.
All you have to do is to (teachers please take note):
1) put the kids in a stressful test situation - a bac blanc in a French public school or épreuves groupés in a private Catholic school
2) demand that they write a poem, under time constraints, on a passage from a text they studied
3) then, with a BRIGHT RED MARKER, scribble all over their poem:
TERRIBLE
AWKWARD
BADLY THOUGHT OUT
AWFUL RHYME
SLOPPY
UGLY
VERY POOR
with blood red circles around the offending portions of the child's poem.
Special tip: Correct the copy quickly with the aid of a "correct response grill" to ensure that no irony, humor, or otherwise subversive stray thought distract you.
4) Make sure that "la moyenne" is less than 10 out of 20 (don't want the little writers to get proud, now, do we!) And, where possible, throw in some nasty oral commentary in front of their classmates as well!
All you writers out there know exactly what this kind of "teaching" moment will do to a person's (and not just a child's) enthusiasm for writing.
If I am furious enough to write this post, it's because an otherwise excellent French teacher at one of France's top middle schools did exactly this. Apparently thinking this was a normal and appropriate way to teach poetry...
Just when I thought it was safe to get back into the French school system.