With my first book Fire, it was pretty straightforward. The story was about a fictional band in the 90s called 'Fire' and that was as creative as I got with that title. The follow up was A Spark before the Fire, which was pretty much an attempt to connect the two titles, letting people know that this book was kind of the prequel to my original book. Also, there is a line in the book where someone referred to the protagonist as 'a spark in the sky'.
I thought my third book, The Rock Star of Vampires, was a pretty catchy title. This was in reference to 'the rock star of vampires' that Ava was attempting to learn the identity of throughout the book.
From that point on, most of my titles come from a line from the books themselves. For example, Her Name is Mariah is a line from the book. This is also the case in Different Shades of the Same Color, We're All Animals, Always be a Wolf, The Devil is Smooth Like Honey, A Devil Named Hernandez and And the Devil Will Laugh.
Having said that, here are some interesting notes. In Different Shades of the Same Color, the title comes from a comment that suggests that we, as humans are pretty much the same regardless of race, religion or any other trait that supposedly makes us different, we're just 'different shades of the same color'.
We're All Animals references a conversation in that particular book where it is suggested that regardless of how soft or fierce we are as human beings, we're essentially all animals led by desires.
Always be a Wolf comes from a line Diego Silva says throughout my last few books, which is that many people choose to be sheep but given a choice, one should always be the wolf.
All my 'devil' titles are in reference to Jorge Hernandez and are books where he's the protagonist.
A title should capture the essence of a book and give readers a sense of the overall theme that awaits them.