See fewer places and spend more time at them. The infamous Contiki Bus Tours can be blamed in part, I guess, for the idea of "seeing Europe in x days" where x is a number smaller than 1,000. Such a thing is, of course, impossible, and anything like it should be avoided almost at any cost.
Nothing is surer to make you go home feeling you've never left than seeing X cities in as many days. It would be better to spend, for example, 4 days in Prague than a day each in Prague, Berlin, Paris and London, no matter the temptation of saying you've "seen it all" when you get home. Fact is, you haven't, and because your experiences are so limited, you may not come back. And that would be a real tragedy.
Take fewer clothes and more money. This one isn't mine, but it is fantastic advice, and possibly the hardest to follow that you'll find here.
The first time you try it, you will be amazed at how freeing it is to simply carry a single change of clothes. I know it sounds like madness, but try it, just once, and you'll be converted for life.
Imagine being able to stay at any youth hostel, for example, and not having to give a damn about security because all your luggage fits into what others might call a daypack. Imagine the search through the mapless streets for your hotel without lugging a 20-kilo suitcase. Without luggage, everything becomes part of the journey. No painful arrivals and clumsy departures in expensive taxis. Catch the airport subway. Daytrip.
Of course, you need to carefully select the clothes that you do take, including one jacket that is windproof, waterproof, and breathable, and shoes that you can walk in all day, and drop a pair of pants over at night when you go out.
Remember: Wherever you go, there you are. This is a very old saw, but take one more look, it's particularly relevant to travel.
You cannot run away from yourself, and if you find that is a motive for you being in another country, you and those with you, and at least some of the people you meet will have a miserable time. If you run from problems they will be bigger when you get back, and you'll spend your time away thinking about them growing. If you run from habits you have fallen into, they will manifest on the road and the disappointment will be enormous.
This also applies to people you meet and might potentially travel together with for a time. Get good at picking those running from themselves, and run from them!
Leave two words behind: "back" & "home". You're not in Kansas anymore. You are the foreigner here.
If things are so great back home, then why are you here? Don't you have such a cute little accent! This sounds so obvious when spelled out, but it's surprising how many people forget this basic rule. You could call it "When in Rome, do as the Romans do" except it's actually more meaningful than mere mimicry for the sake of peace. This point encompasses cultural sensitivity - which is simply respect by another name. Let's face it, noone wants to look like an idiot abroad.
The main point here is that, generally, people have as good a reason for doing something their way as you have for doing it your way "back home".
Remember: Coming home is the hardest part of going away. When I get home, the traveller says, I will be different. I will be changed by my experiences and I will change the world around me.
Sorry. Fat chance. You will be hard-pressed just hanging on to the small changes inside. For most people at home, your month o/s has been a few weeks at work. For most people at home, your enthusiastic stories provoke envy and boredom. Sad but sadly true. You may have thought that coping with strange toilets was hard, but the hardest thing a traveller has to do is keep the magic alive once you're back.