If you want to be a travel writer, watch this Xtranormal animation "So You Want To Be A Travel Writer" It has a lot of truth in it.
Wanna be a Professional?
Professional travel writing, though fun, usually involves things you don't want to be doing on holiday. Admiring different varieties of hotel room, for instance. "Ah, so this is the regular room? And it DOESN'T have the window seat, but DOES have the bath mixer tap? Do show me the Superior room...." You may have to sit in bars and restaurants when you'd rather be outside, listening to breakdowns of visitor figures, or plans for the new marina, or how the city's new transportation project isl revolutionising access for disabled people. Part of the job, but hardly living it up in Rio as the palm trees wave outside, dimly reflected in the tourism manager's computer screen.
Travel Writing and Blogging
But this assumes that you want to be a professional. What if you're a blogger who just wants to get known as a travel writer?
There are some extremely nice travel blogs around, well worth reading and very interesting. They are good because their creators are smart, and they can write. These writers will perhaps pick up some little detail of somewhere they've been, tie it up with some witty overheard comment or funny story. They might put their trip in an historical context, showing how some apparently ordinary place is important, and why they cared. They might combine the travels with some kind of speciality interest - diving, or cooking, and take tremendous photos to back up their words. They probably could do the work professionally, and it would be would be worth these people trying to sell some of their stories to outlets that pay; and get their talent validated with hard cash.
But while some commissioning editors do offer work on the strength of blogs, it is rare. Take a look at Caitlin Fitzsimmons' blog to see what they might be looking for. Caitlin has been offered work on the strength of her blog, but she also has a good body of professional (i.e. paid) work, she has contacts, she is a great writer and she obviously knows the travel business through and through.
Special Blogger Trips
Rather than travel editors, competent travel bloggers are more likely to be contacted by PR companies offering special trips for bloggers. As even popular blogs may only have a thousand readers, and most have considerably less, it's not worth the PRs spending much money, and the trips I have seen (and even been offered on the strength of this blog) are pretty basic. I suspect that so far PRs are not quite sure of the cost benefit analysis of them too.
Probably for the bloggers the trips are fun. The downside is when the bloggers must agree to write specific amounts of copy, use the angle that the PR company wants or submit what they have written for client approval. That is, they are writing advertorial, and this certainly won't impress anyone who might be tempted to take them seriously as a writer or traveller.
Advertorial is the staple of some cash strapped local papers, too. It's found mostly in restaurant columns or travel articles, and it sounds like what it is - rehashed press releases: "We enjoyed a scrumptious meal.... the beautifully decorated rooms had lovely comfy beds... a highlight of our stay was strolling in the gorgeous well tended gardens..." I'm not knocking it by the way. It keeps a lot of people happy - but it's absolutely not travel writing.
The Bottom Line
The bottom line is that you can make a living wage - not good money - as a travel writer by working unbelievably hard, having lots of outlets, including your own online ones, which you need to monetize, and/or by writing guidebooks and / or by getting regular paid work for a media outlet of some kind.
Otherwise, take the advice of the bear in the animation - and get a day job.