Research, Research, Research
The last thing you want to do is arrive in a foreign country without a plan. If you want to learn how to be a successful travel photographer, you must learn everything you can about the location, laws, customs, culture, language, etc. This will help you avoid the common tourist pitfalls and will allow you to get a leg up in the world of travel photography.
One of the most common pitfalls in terms of achieving photographic success is to capture only the most well-known parts of a city or country. (i.e. The Taj Mahal in India, The Leaning Tower of Pisa in Italy, The Great Wall of China, etc.) Of course you may want to visit these locations, as they are certainly magnificent landmarks for a reason. However, if your objective is to show your audience a world they do not know intimately, try and think outside the box when deciding on the best subject material. If you do go back to the old favorites, do your best to capture these locations in a unique and original way; add your own style to every photo you shoot.
Another great tip to excel as a travel photographer is to hire a guide to show you around. Local guides, people who grew up and live in the country you are visiting, will have a vast expanse of knowledge that your typical travel books cannot possibly convey to its fullest. Always seek to find the authentic and intriguing details of the locale. Whether it is visiting a local marketplace or a traveling through part of a town rarely visited by tourists, cultivating a relationship with the local people will allow you to capture an authentic slice of life. Again, this is where taking time to study the culture and, if possible, the language before departure will be a great asset once your plane touches down on the other side of the world.
Finally, regarding research, it is important to build a knowledge base of the local laws and customs surrounding public photography. In countries like Brazil, Spain, or Switzerland, very strict laws exist about photographing people in public. Some countries require a permit to photograph certain landmarks. But in general, even when it is legal to photograph people in public, it is best to approach the situation cautiously – and respectfully – and always use common sense and your best judgement.