I am sure people will recomend some different ways.
I would venture a guess is that one way is to find a single flight from your nearest gateway to Europe, and from there look for regional European airlines which are often amazingly cheap.
Do you live on the eat coast or west?
Another trick is to plan to cruise in October - in the Med it is still great weather (usually).
I am the editor, but I also speculate, ask questions and play devil's advocate. I reserve the right to change my mind.