Things from our parents:
Good girl (my mother does this with Dd often)
Bad girl (my mother never does this one though)
Don't fall, Careful (Dh says these scarred him for life, made him fearful).
...I'll give you something to cry about (my father)
I don't say one more bite. Dd has a pretty good instinct about when to eat, but sometimes she is too exctied about something. I announce, this is when dinner is on the table. if you want this xx yy zz, now's the time. I agree with much of what's been said about the food issue, and that sometimes events and fun may distract the child from her connection with her food needs, and you need to find ways to deal with that:
If I think she needs the protein for her blood sugar and all she wants is noodles, the noodles will ask for cheese to keep them company in her stomach.
Minimal don't, more do's, minimal can'ts, more cans.
Less Oh No! (MIL's answer to everything) and more Oh Yes!
I have a No Selp Deprecation policy: Dd asks my mother to draw something, and my mother says, Oh I don't draw very well, and I invoke the policy if I am nearby. That started when my very self deprecating, brilliant baker sister came and downplayed every compliment at the homemade gifts she brought.
Here's one thing my mother did that still bothers me. She watchs Dd one day a week that I go to work. She knows how I feel about allowing free expression, and one day was very proud of how she handled a situation. Dd bot upset and cried about something. My mother set the kitchen timer and said she could cry until the timer went off. And it worked! Then Dd stopped. She was so thrilled and happy to pass on the technique to me.
I said thanks but no thanks, and Dd still talks about the time Grandma set the timer for her to cry. I told Dd that I want her to express herself fully and let the tears out until they are all gone, and that Dd is the measure of that, not the timer, or anything else, or anyone else.
Dh and I agreed we wouldn't say you are beautiful or smart. But in our own ways, we do, often trying to reinforce the messages by our responses to her actions (thanking her when she's the one to remember where a lost item is, or when she's been kind to someone, and such). Since she's both.
As far as when grandparents do and say stuff we don't, I think that if you set a tone for your household, little ones get the sense of what is for them, and what is the perceptions/styles of others. I don't worry too much about what my mother does or says, because it's what Dd gets from Dh and me that really seems to set her attitude. She just knows that grandma is grandma.