Prior to realizing otherwise, we're pushed and pulled about the world by the whims of our likes and dislikes, reacting habitually without forethought or a moment's hesitation. We instantly become infatuated with what we like, feel repulsed by what we dislike, and then react accordingly. As such, while from the outside looking in it appears as though we're each making choices, little to no actual deliberation has occurred in our decision making process. In this way, we're living in an absence of free will. Rather than acting freely, we can say that we're tethered to our past tendencies.
Meditation practice leads to the development of the skills necessary to witness these habitual tendencies. We begin to see firsthand how reactions arise without our consent. We see how seldom we have consciously agreed to our ensuing reactions. We can see that we're not acting intentionally. As such, in a very literal way, one can say that our reactions are currently beyond our own control.
But now we can see the problem. And we can see how we're complicit when we just follow along as we always have. And then we realize that we don't have to follow along as we always have, that we can make a choice.
During formal meditation practice, this process of the mind wandering off somewhere we never intended, becoming aware of its wandering, then redirecting the mind back to the intended point, develops the same skill necessary "off the cushion" to become aware of when our mind wanders off in a direction we never intended, and then redirect it to an action of our choosing. We can see how we want to react but choose to react otherwise...this is free will.
With dedicated practice, over a long enough time line, we develop the skill of exercising free will throughout the moment to moment choices we make in regard to how we interact with life and the world around us. We become skillful in choosing how we behave so as to ease our own burdens and those of all other beings.