It's not so much that people need special "walking shoes" for trips to Europe, but when you realize a pair of shoes that were perfect for around town or short spurts of walking are suddenly vicious heel-tearing monsters when put to 8-10 miles per day of walking and you end up spending your trip babying your feet and investing in epic amounts of blister bandaids (this has happened to me) that you re-think what shoes/boots are worthy of going on a trip to Europe. That's how I think of my tried-and-true boots, "You've been to Poland, the Czech republic, France and Hungary, aren't you the luckiest boots EVER?" That said, a lot depends on your personal style. I am stylish at home and like to be so when on vacation but first and foremost my feet must be happy.
I travel with 2 pairs of footwear: #1 is a pair of Fly London black laced boots called Yel; their rubber wedge sole was perfect right out of the box and took me over cobblestones, mud, puddles, and anything else you could think of. No blisters, no aches, and very cute. Like walking on clouds. Try Amazon or Nordstrom for a good selection, anything on their wedge sole is divine. Start now, since December will soon be upon us.
The second pair has been Fluevog oxfords called Promise in either navy or orange--I wear them a lot at home and they add some color when I travel. Next trip my second pair will be some Fly London Suzu boots in navy.
Socks: Smartwool in the medium thickness and double-layer Wrightsocks (Amazon has good prices). Even with my perfect shoes and socks I still take bandaids and tape in my purse because one can only be too careful.