Travel photography as a genre is one of the most open in terms of the subjects it covers. Many travel photographers specialise in a particular aspect of photography such as travel portraits, landscape or documentary photography as well as shooting all aspects of travel. Much of today's Travel Photography style is derived from early work in Magazines such as National Geographic magazine from photographers such as Steve McCurry. This genre of photography entails shooting a wide variety of subjects under varied available conditions, e.g. low light photography indoors, available ambient light photography for exteriors of buildings and monuments, shooting on the streets where sometimes conditions may be hostile, capturing moments which rarely recur, capturing the magic of light while shooting landscapes, etc.
However, now only about 10 professional street opera troupes are left in Singapore, drawing an ever-smaller audience of elderly people. The decline of street opera in Singapore was caused by its government's policy to replace dialects (such as Hakka, Hokkien et al) with Mandarin, and the slow erosion of its audience. The spread of television, movies and social media platforms exacerbated the disinterest of the younger generation in this ancient art form.
Whether you're licensing photos through an agency or you're working with local businesses, destination photos sell. If you're just starting out, consider uploading your best work to sites like 500px, where you can offer your images for license quite easily. If you already have a strong portfolio of work, consider applying to Stocksy, the most reputable agency in the stock photo business. Interested in reportage? You can sign up for a Demotix account to get started in travel photojournalism.
I have found Alessandro Bergamini's China gallery to hit all the right notes in that regard. Most of his images were made in Guizhou; a province located in the southwestern part of the country, and well known for its traditional rural villages, inhabited by minority groups like the Miao and Dong. Other images in the gallery were made in Guangxi , another autonomous region bordering Vietnam, and home to the famous cormorant fishermen of Guilin. I haven't been but I read that even though the water is too polluted now for fishing to be sustainable, these fishermen are catnip for many photographers, and earn their living in that fashion.