Never yell or curse at your children. Never call them a name that is hurtful, even if it’s true. I could call my kids ugly all day (I wouldn’t) and it wouldn’t bother them because they know that they are not ugly, but if I use the F-A-T word, OMG! Once you open those doors, you establish yelling and cursing as “fair ground” and are subject to reciprocal behaviors. In other words, you make it OK for them to yell, curse, and call you names. Model the behaviors that you expect.