I went up to Berlin on the weekend to visit friends, and I traveled by train. I've flown there several times, and I have driven, but for me, the train is infinitely better. It's not a short train ride - just over 6 hours - but oh, those uninterrupted 6 hours... what a luxury. I prepare for a train ride with a muted, yet still gleeful, anticipation. It is a time to settle into my seat and watch the scenery fly by, and to read, or listen to music, or watch a movie. Uninterrupted. Have I mentioned that it is uninterrupted? Obviously, that's something that I need every now and then! I also love traveling by myself on the train, and have picked up a few little habits along the way. If it's a morning ride, I always pick up a chocolate croissant and cappuccino for the ride. If it's an evening ride, I pack myself a sandwich, and I make a detour through the restaurant car for a beer.
And then I just settle into my seat and relax for the rest of the ride.
My favorite time to travel by train in Europe is in winter. It's less crowded, as all the Eurail Backpackers have gone home, and the landscape outside a train window is perfect when blanketed with snow. I love to see rolling white fields, and church spires in the middle of a village hovering just over the next hill, and trees bowing under the heavy weight of snow. It's just... lovely. I even like waiting on the train platform in the cold, my mittened hands wrapped around a coffee, and my breath creating little puffs of vapor in the air. Well, as long as the train isn't too delayed - there is a limit to my crazy!
So, given this love for train travel, I have learned a few little tricks that help to make train travel even more enjoyable (and affordable):
Travel in a Group
Okay, I know I already stated that I love to travel by myself, but this is a special tip to make train travel more affordable. In Germany, infrastructure/public systems are often designed to accommodate families and students, and to make things like travel generally more affordable. These designs often translate into a "group" discount (e.g. as opposed to a "family" or "student" discount specifically). So you can almost always buy "partner tickets" of various types that allow up to five people to travel on one ticket. Two of the most well-known tickets of this type are the Bayern Ticket (a day pass allowing travel anywhere in Bavaria, and even to Salzburg, Austria on any of the regional trains) or the Schönes Wochenende Ticket (similar to the Bayern Ticket, but good for the entire country, and only on weekends).
Book Train + Hotel Packages
When I am traveling alone or with one other person, it often ends up cheaper to book a package train + hotel deal through one of the German travel agencies (try www.ltur.de). The train ticket is usually flexible - you can use it on any train on the specified days of travel - and even if I trash the hotel portion of the ticket and stay with a friend instead, it still costs less than a full-fare roundtrip train ticket.
Travel Last Minute
If you are really flexible, there is such a thing as Restplätze whereby unbooked seats become available between 1 and 7 days before travel, on certain trains anywhere in Germany for 26 Euros. The trick is that you never know which trains will have availability, and the prime time to find such deals is two days before travel. So if you need to be somewhere specific at a certain time, this is probably not the best way to travel. But if you feel like just jumping on a train and going somewhere on the weekend, definitely worth looking at.
Take your Car on the Train
I haven't ever actually done this, but Germany (and other European countries like France and the UK) have car trains that will transport your car from one end of the country to another. I've been told that it can be cheaper than paying for gas, and it's often an overnight trip in a sleeper train, so far more comfortable then having to drive through the night.
Sit in the Restaurant Car
Sometimes the trains are really crowded, and if you don't have a reserved seat (it happens) that means you could be in trouble, or at least uncomfortable, standing or trying to sit on your bag for a few hours. In such cases, instead make a beeline for the restaurant car and settle into a booth for the duration.
I'm sure I have a ton of other tips, but these are my most trusted "insider" tips (e.g. beyond the oft-repeated advice to buy your tickets in advance - that does save a lot of money, but buying tickets 3 months in advance means that you are extraordinarily organized - far more than I). Now, go take the train! Despite what you may hear, it is a very romantic and enjoyable way to travel.