Yiddish slang meaning "gimmick" that has come to mean "someone's signature behavior." In the 1940's, Jewish comedians in the Catskills referred to their comedy routines as their schtick.
presentation or sales pitch, from yiddish slang, implying phoniness or slickness, lack of substance with focus on style.
Grandma Zeidel gave her usual shtick for serving take-out for dinner instead of cooking, claiming that her oven was broken and the cleaning lady forgot to do the dishes again.