No doubt some of your clients have asked for help to stop unwanted habitual behavior, and then been surprised at how difficult that can be. Always looking for a powerful metaphor, I was delighted to read, in David Eagleman's Incognito, about the fanciful German expression innerer schweinehund or "inner pigdog" -- referring to the part of us that wants instant gratification no matter how firm our dedication to a long-term goal.
Neuroscientist Eagleman points to Christmas Clubs as one type of solution to the arm-wrestling between short- and long-term desires: give it over to someone else. I must admit I've tried this with my addiction to Wedderspoon's Munuka Honey and Ginger throat lozenges, asking a friend to hide them from me or I'd never have any on hand when I actually have a sore throat. This worked for a while, but finally I just quit buying them.
Eagleman retells the story of Ulysses, who knew the dangers of sailing past the island where the Sirens' music was so alluring that passersby steered to their deaths on the unforgiving rocks. Before approaching the island, he had his men lash him to the mast, fill their own ears with beeswax, and instructed them to ignore his pleas as they sailed past the Sirens, no matter what he threatened. Knowing his innerer schweinehund would opt for immediate gratification, he structured a future where he could count on satisfying his long-term goal. Thus a freely made decision that binds you to a future outcome is called a Ulysses contract.
This is why many coaches ask for commitments from clients, and talk about holding clients accountable for what they've said they were going to do. Though this makes a kind of logical sense, I don't think it's a good idea for coaches to make Ulysses contracts with clients. Yes, it's useful to know their wiring naturally creates a struggle between opposing forces, but I'd rather help people strengthen their own ability to dedicate themselves to a desired future. Because of this, I only hold clients accountable for what they DO, not what they said they'd do. We pay attention to how the inner pig dog operates so we can learn where and how to begin changing the wiring.
(Eagleman also wrote the fictional Sum: Forty Tales from the Afterlives.)