Onstage and off, Dessa exudes an aura of classic cool. Not by dressing up, but dressing down, the rapper/writer/singer struts a style that’s bold and confident yet simple in execution. “I look to people who are a little more androgynous,” she said. “James Dean, for example. … I like his red coat, his plain white shirt and his fitted jeans.” Add a pair of silver hoops and a ponytail, and you have Dessa’s quintessential look. Here, Doomtree’s leading lady dishes on her favorites. (Catch Dessa’s next show March 28 at New Century Theatre.)