You know me and hair. The first thing I picture about any new character is their hair. So when my protagonist, Tansy, in my just-sold fairy novel Named and Shamed, describes herself this way:
"Most men get no further than some reference to Amazons, because at six foot tall and with a rack like this I can't help but invite the comparison. Add to that my red hair—not an insipid ginger but ferociously bright metallic waves—and pale skin that explodes into freckles all over my shoulders and arms at the first touch of summer ..."
... I had to go looking for a visual model.