Calm parenting

I try very hard to calmly parent my children, this does not always work mind you! I have a few areas that I don't really compromise on, but otherwise I try very hard to keep my cool and not explode under what can be trying circumstances.
I expect my girls to eat their meals at the dining table with some sense of table manners. Now I am dealing with a three and a five year old so I am not expecting them to use formally set cutlery, nor do I expect ALL food to remain neatly on their plates. In the future I would like these things to be within their grasp so I stick to my guns! I do expect them to sit properly on their chairs and to use the appropriate tools to get their food from their plates to their mouths. That means spoons for breakfast cereal, nice clean hands for sandwiches and knives and forks for Sunday roast. I expect them to chew with their mouths shut and to stop the yelling and mucking around while at the table. The kids know the rules and they are very good at sticking to them. It makes family meal times generally fairly pleasant. To get the rules across to the kids we gently remind them "please close your mouth" or "I think that needs a fork" etc, we also lead by example! At lunch today we had some issues, Bug decided that she would make things difficult, she sat, or rather knelt, backward on her chair, leaned over her sister to grab things and was in and out of her chair at a rapid rate. So the warning was delivered. If she got out of her chair again or didn't settle down then she she would be sent to her room until everyone else was finished and then would have to eat her meal alone. She settled down for about two minutes then leaped out of her chair to dance! So I calmly asked her to head to her room, this is where it all feel down. First, Bug yelled, then she started jumping up ad down and yelling (she is talented!) So I took her by the hand to lead her to her room, she resisted. I explained that I had warned her about her behaviour and now she needed to deal with the consequences. Bug yelled, but reluctantly headed to her room where she continued to cry and yell. I had hoped that by age five she would be getting the hang of the consequences in response to actions deal, but it appears not. About 5 minutes later Bug wondered out again and wanted to tell me a story about the game she had been playing, she behaved as if nothing at happened. I would have like an apology but I wonder if I am expecting too much from her or if I am not consistent enough for her to understand what I am getting at. Does anyone have any tips? Anything that you use that works wonders?