I dont know how to make my dog stop nipping

Hi, i just got this dog a few days ago. She is 1 year old, German shepherd terrier mix (we think). She is a rescue, and extremely well behaved besides the fact she has a really bad habit of nipping when she gets excited/happy. This is my first rescue and my first time having this breed. The majority of things Im reading is aimed at under 6 month/puppies. Does anyone have any tips? What im doing now is sternly saying "no" and then I stop petting/talking to her for a few minutes untill she stops. Is there a better way to correct this behavior?