One of my favorite classroom activities in my Composition classes was to put the students into small groups, then ask them--as a group--to come up with the most poorly written sentence they could come up with. We did this exercise in the middle of the semester, when they had learned enough about grammar, diction, and punctuation to know how to break rules. The students then put each group's sentences on the board, pointed out all the errors in the sentence, and we voted on the best (meaning worst) one. The students had so much fun doing these, and I always got to laugh a lot myself, which does not happen a lot in those Comp classes.
Taking a cue from this exercise, write the worst poem you can. Use all of the things you were told along the way. Use cliches, overdone rhymes, awkward syntax, antiquated and technical diction. Stick punctuation here and there. Mangle line breaks and metaphors. Write about a huge topic without any details. Give the reader nothing while at the same time hit the readers over the head with your "deep meaning."
Then send this poem to your dream publication . . . kidding!
Find something in your poem--it could be a surprising phrase, a weird stanza break, a simile that stands out--and use that in a new, good poem.
I used to tell my students, after our exercise, that they had gotten all of the bad writing out of their systems and would all only write A+ papers from then on. Same goes for you! (Kidding again.) But I encourage you to print out or rewrite legibly your bad poem and put it near where you revise your work. Use it as a "Never Again" reminder.