Be prepared for the possibility of riding in a not-so-well-kept vehicle. Not every taxi is a luxury car, as in any city in the world, but ours in particular was a death trap. I had no good seatbelt, and my door could not be opened from the inside. Not really a warning, but just to let you know what you could encounter. Also, it is good if you know another language other than English, preferably a European one. I was travelling with a German friend, and I am fluent in Spanish and competent in German. Just for my sake, to avoid the possibility of being taken advantage of by the taxi driver, I didn’t speak a word of English, not even with the driver, and I switched between German and Spanish with my friend. (The driver spoke only a little German.) I also never mentioned it was my first time in Prague, and tried to act as unimpressed as possible (which was difficult in a city so beautiful!) when the driver was pointing out “points of interest.” Yeah, I know it sounds extreme and paranoid, but when we got to the hotel, the clerk told us stories about how English native speakers were being charged in the neighbourhood of 45 Euros for what should be a MUCH cheaper trip. Also, if you have a metro pass, you may also want to consider taking the subway to the train station. It was a quick trip from our hotel to the station, not so much of a hassle, and, or course, the cheapest way.