以身作则 ------- set a good example for/ to others

例句：
A: Don't ask others to behave themselves all the time. You have to set a good exmaple for/to them too.
不要老是要求他人行为要规矩，你也要以身作则。
B: Of course. Being a teacher,I should set my students a good example.
当然。身为老师,我应该给我的学生树立好榜样。

同义词：
practice what you preach