Herbert wrote and performed in a solo show, My Weekend with Pablo Picasso which features his skill at painting and has been performed at the Los Angeles Theatre Center, and the San Diego Rep. He wrote and performed in another show, ¡Cantinflas! about the Mexican comic of the same name, which was co-commissioned by the Alley Theatre in Houston and Yerba Buena Center for the Arts in San Francisco. Other work of Siguenza's includes Steal Heaven, and El Henry, an adaptation of Shakespeare's Henry IV which was presented at the La Jolla Playhouse in June 2014, and Manifest Destinitis which premiered at the San Diego Rep in their 2016-2017 season . In 2016, Siguenza began a three-year Playwright residency at the San Diego Rep as a part of The Andrew W. Mellon Foundation's National Playwright Residency Program, administered by HowlRound.
