this is an interesting topic. I would say that your Dom should be able to read you well enough to tell when you are going to balk at a task. I think one of the hardest things about Domination is knowing how to move towards your subs limits without crossing them.
I guess for me the game isn't about breaking my sub, but conditioning her. allowing her to find pleasure in the activities we do, providing that carrot on a stick to lead her where i want her to go.

It is also important for you to be truthful with your Dom. that is a huge part of the relationship. If your Dom doesen't know what it is that you want/like or hate/don't want, how can he make the scene good for both of you? clear communication outside of the scene can allow the Dom to create a truly wonderful experience for both of you, Imho.