Your copy-cat toddler will experiment with words you use often. If you're tired of saying, "no" and "don't," switch them out. You could substitute a clap or the word "danger" for "no." Try telling your toddler what you would like, for example, "set your toy right here," instead of "don't drop that."
It's time to play emotion coach. "Sara is so mad that her toy tipped over." "I see that you're afraid of that dog." When you first see your toddler's frustrations coming on, get down eye-to-eye and in an exaggerated tone, name the feeling. Kids begin to develop empathy as they themselves feel understood.
Some defiance by your toddler can be a good thing. Your child is trying to assert that he or she is a real person with a small amount of pint-size power. This behavior is totally appropriate. It's okay to say, "no" whenever appropriate and without compromising safety, health, or other peoples' rights.
Try to side-step power struggles. For example, let your child be in charge of his or her potty training. Kids all get out of diapers sooner or later. Nobody wins fights with your child about his or her body.
Here's another suggestion: Put your toddler in charge of feeding themselves. You furnish the healthy food choices (or it might be cake for every meal). Your child decides what and how much to eat. If you think your on-the-go child doesn't take the time to eat, add a bed-time snack.
During the toddler years, your baby is growing into his or her own person. Your challenge is to keep your sanity and hair. What's helped you and your child survive the terrific, terrible toddler years?