This is a VERY good question. Europeans dress nicer than most Americans do. You’ll want to blend in and not LOOK like a tourist to help avoid those pick-pockets. If you don’t want to look like a tourist, avoid shorts, halters, sleeveless shirts. In Europe, these items are considered beachwear and you may find yourself a target just by wearing your normal summer clothes. You’ll also want to avoid packing those JUICY sweats outfits.
For starters, pack light. Try to pack only one bag – and limit it to 20lbs. If you can’t find a taxi, you’ll be the one lugging your bags to and fro so you’ll want to make sure you can carry everything you bring. An unstructured 9" x 22" x 14" bag should fit under most airplane seats and it will certainly fit in the overhead bins. You will want to pack clothes, toiletries and electronics, so keep that in mind when deciding what to take.
Pack less. But you are going to Europe for 10+ days, how are you supposed to pack less? Spend some time (perhaps every third night) doing a little laundry. And pack items that you can match up differently. After you’ve done a little bit of laundry, you can create new outfits so you don’t feel as though you are wearing the same outfits over and over again. This is the best tip for clothes, considering everything else you will want to take along in that bag of yours. Keep reading, you’ll see what I mean.
You’ll be doing a lot of walking, so be sure the pair of shoes you bring are comfortable walking shoes. It’s best not to buy a new pair of shoes for your trip. You won’t want to ruin them right away if it rains, and you wouldn’t want to get blisters on your feet the very first day. That would make for a miserable vacation. Aside from the one pair of walking shoes, I would bring ONE extra pair of nice dress shoes, so if you go out for a nice evening, you don’t show up in a dark pair of Dockers with bright white (or dirty and scuffy) tennis shoes.
Pack dark colors. Dark colors don’t show wrinkles or stains. Black goes with everything, so you’ll be able to create many different outfits. During warmer months, jeans may be too heavy and hot, so you might want to find some lighter weight slacks to wear.
During tourist season, many concert halls go casual. You should be able to get away with casual pants such as Dockers and a nice top.
Tie or scarf can gain you instant respectability. If you want a table at a nice restaurant for dinner, you should take something like a tie or a scarf to ‘jazz up’ your outfit.
I read an article by Rick Steves and I think he said it best:
“But ultimately — so long as you don't wear something that's outrageous or offensive — it's important to dress in a way that makes you comfortable. No matter how carefully you dress, your clothes will probably mark you as an American. Frankly, so what? Europeans will know anyway. I fit in and am culturally sensitive by watching my manners, not the cut of my clothes.”
Electronics: When packing, keep in mind that you may want to take some electronics with you. You won’t find a hair dryer provided in hotel rooms unless you are in a very nice hotel – and then you can’t guarantee there will be one there waiting for you. Find yourself a small, fold up, travel hair dryer and don’t forget to pack an adapter because European electrical currents are not the same as in America. And make sure the adapter is suited for where you are traveling. British/Irish outlets have different prong configurations than the continental Europe outlets.
When you get to Europe, you may want to visit a hardware store for a three way plug adapter. Many hotel rooms only have one outlet, but you have camera chargers, phone chargers, and the room light that you want all plugged in.
Now that you have all of these items in your suitcase, do you have enough room for souvenirs? You may need to pull one or two items OUT of that suitcase, so that you have room for the items you pick up along your travels when you return home. (Remember, you will want to do laundry a few times during your trip, so go ahead and take one or two outfits out of your bag.)
Additional information:
Rick Steves suggests the following for your Documents:
“Bring your passport, plane ticket (or e-ticket printout), railpass or car-rental voucher, driver's license, student ID, hostel card, and so on. Photocopies and a couple of passport-type photos can help you get replacements more quickly if the originals are lost or stolen. Carry photocopies separately in your luggage and keep the originals in your money belt. In your luggage, you'll also want to pack a careful record of all reservations (print out your hotels' confirmation emails), along with a trip calendar page to keep things up-to-date as your trip evolves.”
As an added backup, provide a copy of your passport to your Travel Agent. If you lose your passport, a quick call to your Travel Agent and they can begin requesting a replacement for you while you continue your trip and provide copies to any customs official when you need it.
Packing help: You may want to go out and buy some of those compression bags. You can pack your underwear, socks and other knit items in these bags which will give you more room for other items in your bag.
Guidebooks: Don’t pack them. Tear out pages from the books and staple them together. You can also print out information from the internet to take along.