As with all types of photography, smart business sense is key. There are many ways to make a living with travel photography, and much of it extends well beyond your photo gear into social media marketing, content development, negotiation and sales. But the first step is to get out into the world and shoot. Start with anyplace you've been dreaming of traveling, and go! Plan ahead, do some research, and don't shoot like a tourist. Can't afford to travel? Search for opportunities in your nearest city to begin building your portfolio.
When you are photographing buildings, statues, or other monuments, think about what they represent before you shoot. For example: There's a large statue of Vulcan outside Birmingham, Alabama. You could make a perfectly nice image of him standing on his hill on a sunny day, but such a picture would not say a lot about who Vulcan is. A photograph on a stormy evening, with perhaps lightning in the background, would. Cannons on a historic battlefield might look better in fog than in bright sunlight. Get the idea of the subject, then think of the weather, light, angle, etc. that best communicates it.
Besides the travel publications like National Geographic Traveler, Conde Nast Traveler, etc., the demand for this genre exists in industries like Travel, Photo Education, etc. Many travel photographers are today leading photo-tours through companies such as Intrepid Exposures, utilising their knowledge of unique travel locations, experience of working as professional photographers and using this to help travel enthusiasts take great travel images during their trips. Many others are doubling up as educators in the field of ambient light photography. Some of them are doing assignments which intrinsically use their strengths, e.g. shooting exteriors or interiors of buildings for architects and interior designers. Photographers like Steve McCurry are often commissioned to shoot commercial advertising work using their skills from travel and documentary photography to produce powerful advertising images.