My actions are the intersection of my promises.
Calculating that intersection is a continuous, complex operation. Some of my promises are narrow and explicit: "see you at 4pm". Some are long-lasting and legally binding: "I will carry out the fiduciary duties of a director". Some are overbroad: "I will protect you". Some are to myself: "as god is my witness, I am going for a run today".
But I'm at my most miserable when there is no longer an overlap. It's quite easy to do this accidentally, either by losing track of a promise, making an ambiguous one, or a simple change of circumstances so that two things that used to overlap no longer do. It doesn't matter; nobody but you cares about the reason you let another person down.
My freedom, my maneouvering room, is the remaining size of the intersection. I'm learning to keep an eye on it; in some domains, it's space left in the schedule, in others I can model it in financial spreadsheets, and sometimes it's just a feeling of uneasiness as the number of possible courses of action that still fall into the overlap starts to shrink.
The other time I'm conscious of this diminishing freedom is when I'm cycling through traffic. Here, the 'solution space' is all the places I could still go in the time it takes to stop. Even in complex situations, I won't hit anything unless the space goes to zero. I remain acutely aware of it; the ebb and flow of traffic opens and closes options all the time, but as the options narrow, everything becomes more dangerous.
I'm learning to use this as a warning. I keep an eye on how many of the possible combinations of circumstance and action fall inside the intersection, and as the proportion falls, it's a cue to stop making any more commitments. Even if the new promise doesn't immediately and obviously clash with another (which would, conveniently, provide a good reason not to make it), it will act to reduce the solution space. At that point, failure in some form is inevitable, even if it doesn't seem related.
I try not to make promises I can't keep, even if I don't yet know why I won't be able to keep them.