When I ask Maia to come in when she is far away, or to allow me to halter her when she'd rather eat hay or graze, she generally likes to be given the chance to say "No".
Her "No's" never last long and can be quite entertaining (depending on her mood they can even be explosively spectacular--awesome feats of acrobatics and/or hilarious displays of athleticism and speed--I have posted such displays often as they are glorious!).
The beauty is, it's always fun to watch her reactions, gauge them, and then define in the moment how best to help her decide to change her "No" into a "Yes".
It has taught me a lot about timing and feel and the importance of not taking her reactions too personally, making sure my internal energy matches my external body language, and being patient and calm or energetic as needed.
In the end, when she accepts my request with a sweet "yes", she has done so on her own terms, knowing that she was free at all times to express herself, feeling no resentment or powerlessness, and appreciating that her way of feeling and of being are honored and not punished.
I swear it makes her want to be better for me! (I know that's how I feel when people treat me this way!)
Even more important, saying "Yes" begins to feel good for her.
So, when I ask another day, she may not even want to say "No." And this good attitude always pervades any other activities we might do together: groundwork, riding, ponying.
The point is, I could train her to not even THINK of saying "No," but I'd rather she have the freedom to think of saying "No," but then realize that saying "Yes" always feels better.