This is a tattoo design made for a friend, of the Indian patron deities of dance, Shiva and Parvati, in their combined form of Ardhanareeshwara, which is a composite figure which is half-male and half-female. 

To start off, I sketched a few quick dynamic poses, of which two were detailed further in a pencil/ink sketch. Of these, one was chosen and illustrated in a single-line form. A few alternate versions of the single-line illustration were considered before deciding upon the final version you can see below.