Just booked flights on Aer Lingus -- Chicago to Venice/Rome to Chicago -- for next May for less than $1,000 apiece. Last year, I spent months and months obsessively checking fares multiple times every day, only to finally panic and purchase at exactly the wrong time. We flew Aer Lingus last year and were totally satisfied, but this fare will be almost $1,700 less (for three of us) than we paid then.
Best part is that now it's done, many months in advance, and I can move on to fun stuff, like getting signed up for the Venice-Florence-Rome tour.
I had to push my dear, cautious wife to commit this early, but as many experienced travelers have suggested, if you find a decent fare with a comfortable itinerary, just grab it and never look back.