I always research. Although, the degree of research depends on what piece of work I'm writing.

Right now, I'm about to begin a contemporary romance with my hero in the espionage occupation. In order to have my guy true to character, and be able to give real facts, I have to research like crazy. I have also researched the city for the setting of my book.

While working on a fantasy, since I'm building my own world there, I have been known to look up different types of fabrics that would be worn in the climate in which my story is set. And the weaponry my characters would use based on resources available to them.