How do we teach dogs to ask politely instead of saying "gimme"? We teach them being pushy, barky, and demanding gets them nothing, and that a simple sit gets them all the good things they want. Food, water, toys, access in and out of the door, and attention are all important resources that they learn to work for. Cora is catching on that barking and jumping gets her nothing so she's offering a sit much faster now!
Good things come to those who sit!