Like most things, I do my research. I cant see how anyone can write a story without understanding the world or the technology/magic they are using. In Seeon, i used transporter and other technology seen in Star Trek or other sci-fi books. I clearly designed one part of the world to be behind the curve, misusing the technology they have gotten, while the rest works to benefit everyone. Background understanding was necessary.
However, I'm more likely to do research on various mythological creatures and forms of magic to use in my stories. Even my favorite comic characters are researched. Wonder Woman's bracelets are made from Zeus' shield, Hawkman and Hawkgirl can fly and more due to Nth metal, and the list goes on.
I am not one to let a character live just because he was shot and I like them. Everything must make sense for the world it is created for. Sometimes, it is easier to kill them and deal with the fall out, or injure them and make them a more interesting character.
Anyway, just my take.