Tomer Hanuka explains his approach to the cover for The Kiss Murder:

Illustration is like acting. you need to invest a strand of authentic emotion to make it work. otherwise it feels artificial. So you try to embody, in your head, the protagonist. Let’s see: you’re a slender man of Turkish descent who’s a computer wiz, a private detective, a black belt and an Audrey Hepburn look alike. most prominently you are a transvestite. you sit in your night club, ready to punch someone softly or kiss him to death. either-way it’s a deadly move. and then an epiphany: it’s in the shoulders– that potent combination of strength and sensuality. a pair of slender, well defined, boney yet muscular shoulders. a glorious pedestal for your pretty face.

Step by step in the link.