When I have broken up with people in the past, i have found it quite therapeutic to write them a letter....but then never send it to them! Destroy it! It is good to get your feelings out on paper, write down the stuff that used to annoy you about him...and just get your feelings out of your system, and then onto the paper.
Yeah, it sounds like a lame idea, but it has worked for me (also written letters, but never sent them to my boss and mum about how much they pi$$ me off!)
It makes me feel better anyway...