I'm not quite familiar with the underlying subcategory of this node - how to ruin poetry by reading it
.. sorry Muke
. I am, however, quite familiar with the subcategory how to ruin poetry by writing it poorly in the first place
In my opinion, any of these ways works. Make depressed poetry rhyme - Rhyming gives a lighthearted feel to the poetry, ruining anything with a dark undertone Make it trite - Try not to say something someone else has said before you.. or at least, not in the exact same way. Try to come up with your own magical phrases that ellicit emotions from the reader.Use Iambic Pentameter - Shakespeare was the master of this. You are not Shakespeare, so pick your own rhythm. Make it fluffy - This works for me at least. All my happy, shiny poetry is absolute CRAP.
This is all I have on the top of my head, besides my hair. Will add more as it pops up.