Take ONE pair of shoes and make it work!

If travelling through Europe, seriously consider one of the Eurorail passes - we saved over 700 Euros with the 5-country, 15 day travel pass.

Ask at the hotel/hostel counter where the locals eat. Not only will you have a better chance of finding authentic cuisine, but you'll be more likely to not get ripped off on the price. Be prepared to play charades for ordering and try to know enough of the local language to figure out what you're ordering. If you find a place with wifi, you can use google translate to identify your dishes.

Pack less shirts than you think you'll need, you can always wear a second time, you'll find a place to do laundry.

Pick out your hostels ahead of time and reserve if you have a solid plan of dates. There are a couple of sites that are good for booking hostels in the accomodations section. Some airports are cheap and don't have free wifi! Don't expect it.

Around town you can sometimes find wifi at Starbucks, McDonald's and even some little cafes have it avail with no password!

Try to have a list and map of the sites you want to see before you go, especially if you're only there for a short time, you don't want to waste it looking for things to do.

Take the walking tours wherever you can, you can likely see some of the sites on your list so you can find them later when your map fails you and the tour guides can pump you full of historical facts you wouldn't learn otherwise

Some guides talk too much/long!

Meet people! A good opening line seems to be 'where are you from?' If they've been in town for a while, they might be able to give you some ideas of what is good and what isn't. You might also get some ideas for your current/next adventure. Sometimes it's cheaper to split the cost of a hotel vs. individual rates at a hostel, but you have less of a chance of meeting people

Get lost in each place you go, eventually you'll find your way back and you'll see things you wouldn't otherwise.

Spend at least a whole day in Salzburg and a whole day in Vienna!

Prague and Salzburg are beautiful and would be a really romantic place to go with a 'significant other.'

If you're going somewhere off the main path, be really good at charades because there's less of a chance English is going to work if it's not the first language

Don't exchange currency at a train station or airport. While the rate is excellent, they get you with the 'unadvertised' service fee! In Prague it was 17%!

Keep a journal (this site is a good place!) put in reminders if you don't have time to keep it updated so you can go back and fill in the blanks.

Bring earplugs if you can sleep with earplugs in - you don't always get to pick your roommates in hostels

Keep currencies separated!

Don't bother mailing postcards unless you can buy single stamps, you'll get stuck with extra stamps that you can't use in the next country.

If you need it, look for places to stay that say 'free wifi' in their ad. If it just says 'wifi' it's not free

Delta airlines has flights that offer one free checked bag - I really appreciated this when booking my flight