This article from Bookbub, surveying book titles, illustrates the most popular title words in thirty-three genres. http://insights.bookbub.com/title-trends/?et_mid=779566&rid=240999278
Your book title — along with your cover — is the first thing a potential reader sees, and can be the deciding factor between hitting the buy button or not. Your title is a great opportunity to indicate genre, plot, atmosphere, or characters. […] Each genre has its own title conventions, and studying the other titles in your genre, especially those that have been selling well, will help you learn how to target your audience.
You can go through the slideshow at the link to see the word clouds for each genre. Here are the highlights of the most common — and theoretically most effective — title words by genre. I found this very interesting.
LOVE – Romance, Contemporary Romance, New Adult, Chick-Lit, African American Interest
LIFE – Women’s Fiction, Literary Fiction
WOLF, BLOOD, DARKNESS, MOON – Paranormal Romance
MURDER, KILLERS, SERIAL – True Crime
DEAD – Horror, Supernatural Suspense
JUSTICE – Thrillers
MURDER, DEATH, DEAD – Mystery
STAR – Science Fiction