I’m seeing Dulles-ZRH $906 outbound last week of May. Also check out our new user thread—top of this forum—for strategies and links.

I’m also seeing some nice fares to Dublin ($617 if outbound by May 25, for example). From Dublin, you could add-on Italy, and come back from BCN, with Ryanair or Aer Lingus. With Aer Lingus (which doesn’t fee you to death as much as Ryanair does) I see DUB-VCE $50 late May, and BCN-DUB $78 about 3 weeks later. If you add extra flights on your own, just be sure to allow plenty of time to avoid mis-connection. Adding Dublin for a day or 2 might be a bonus if you hadn’t considered that.

Also check the consolidators in our new user thread—for multi-city flights too. I need to update that thread to include Cfares as a really good multi-city flight search.

You may want to sign up for fare alerts for itineraries like DET-BCN, DET-ZRH (and/or GVA), WAS-BCN-WAS-ZRH. Also check here often since people post when sales pop up. Last year there was a really good U.S. Air sale during the third week of January and I’m hoping we’ll see some sales in the next few weeks.

I like to plan a loose itinerary before starting to look for airfare, because you can then limit your search to looking for flights in only a couple of locations. After having my loose itinerary, I look for a flight, because then I have dates to plan around.

Absent sales, I think a good general rule is that you get the best prices by flying out of places that have a lot of competition. Newark, for example, has many carriers using it, so while it is crowded and hectic, the prices out of there are often better than out of places like Washington or Detroit. But you may certainly find a good price anywhere if you are willing to spend the time looking.

As an aside, you are listing 13 places you want to visit in 21 days (19 days if that includes your out and back days), and with travel taken into consideration, you probably won’t have a full day in any one place. I think it would be best to pare your itinerary dramatically, perhaps flying into Venice, then doing Milan (many people say Milan isn’t worth a visit), then Florence, a few days in Cinque Terre, then Rome and Naples (consider a day in Capri from Naples), and fly home from Rome. That is still a crowded itinerary for 21 days, but at least you will have time in each location to settle in and see what is most interesting. Every novice starts with an impossible itinerary, and it takes some experience to see how long you enjoy staying in one place. Last year we spent seven days in Rome, and four or five in Naples. We didn’t get to see everything we planned to in Rome, but Naples worked well for us, but our interests may be very different from yours. Just to see the interior of St. Peters takes at least half a day, most of it spent in line. The Sistine chapel is another half day.