Yeah, I know, like three trips to Europe in 45 years makes me a travel expert. As with most other subjects, though, I do have some observations.
My brother Ron, who was a pilot for Delta for 27 tears, says "travel is a curse." It can be sometimes, but it's also the only way to get anywhere. (Profound observation, I know.) I am still in the throes of jet lag. I figure I'm four and a half hours off sun time. This morning I woke up at 4:30 AM, but I'm working my way back. Ron says you can count on one day for recovery for each time zone you've crossed. He also says pilots advocate alcohol and sleep to recover from jet lag. (That's a joke! Please do not call the FAA. Besides, he's retired.)
Going to Europe, we were told by several people who have made the crossing a number of times to try to sleep as much as possible on the flight. When you reach Europe, ignore the facts that your body is screaming that it is 2 AM. Take a nap for an hour or so and try to get on local time. Food helps (it always does, doesn't it?).
I think everyone knows that aircraft interiors are dry and that you should try to hydrate yourself as much as possible. I drank eight ounces of water an hour (which meant I had to squirm my way out of my steerage-class seat about four times to go to the bathroom) but even with that by the end of the flight I could feel myself drying out like Sponge Bob Squarepants left out on a rock in the sun.
Westbound seems to be worse. It might be that I'm exhausted by all the fun we had on top of wrenching my nervous system out of joint (if nervous systems have joints).
I would also say to try to learn a little of the language. We felt quite helpless in German where my command of the language was what I could glean from World War II movies. "Schnell!" and "Hände nach oben!" are not useful for ordering in a resturant. Even my passable but not fluent French I had to struggle. Mercifully a lot of people seem to speak English in tourist areas, but I don't like to count on it.
Then there's packing. This time I had the Great Washable Packing Fiasco of 2011. We were told to pack lightly and take smaller suitcases than the airlines allowed since luggage space in European buses is less that in airplanes or American buses. (So are the seats.) My solution was to take quick-drying clothes and count on them drying overnight. I even tested everything at home and it seemed to dry quickly. Then our first hotel room was like a humidity chamber. A row of trees impeded air circulation through the windows and nothing would dry even after three days. Becky squeezed as much as she could out of my clothes and blotted them with towels, and I ironed them and used the hair dryer on them. A less humid room at the second hotel set everything right but it was a close call. After this experience, my advice is to forget packing light and take as much as you can. take things you think you'll never need. That's why suitcases have wheels.
The last bit of advice is to train for the trip. Seriously. I had upped my walking for a month before we left but still had aching calves and sore feet. Touring is strenuous to say the least, so it's best to be prepared for it.
Also, take a week off when you get back and do as little as possible. Oh, wait, I'm retired and can do that. I'm sorry if you can't.
Expect the unexpected. After all, travel is an adventure...and a curse.