The Power of Now by Eckhart Tolle.
Promoting “breathing” without thinking and not taking your thoughts too seriously has got me through a lot of emotional turmoil and “life situations”.
Incredible even 5 years later.
As you allude to, the basic idea is the same stuff you've heard if you've read anything about "mindfulness." Basically a lite Buddhism -- a lot of your unhappiness comes from a constant spigot of unbidden thought you can't shut off and you can improve your life by learning how to shut it off and be absolutely focused in the present moment, through exercises like meditation. I think this is a bit oversold but not bad.
But that's not really enough to have a media empire and series of books, so the book is larded with all kinds of ridiculous claims, including risible Biblical exegesis, an attribution of various historical atrocities live Kristallnacht to a failure to like In the Now, an extended discourse about how living In the Now can make menstruation a rapturous experience rather than a painful one, and obviously bogus claims about how living In the Now will actually cause the molecules of your body to spread out and make your body less dense.
The point with these therapeutic visualizations is to try how they work, personally, as an actual tool to solve a concrete dilemma. As such it does not matter how useless they sound in written form. Human mind has these psychlogical switches that just seem to work in specific situations. For example of a pathological "switch", the gambler is lured by an unpredictable sequence of loss and reward. Which to most people sound extremely silly, until they try it out themselves, and are totally hooked. Therapeutic switches can seem to have equal power to deal with ones emotions and pain.
For me, visualizing my pain as a separate entity that fed from my suffering allowed me to conceptualize my internal pain in a way in which I could observe and deal with it better.
It's like how some yogis speak of energy flows and whatnot - which is completely inconsequential hogwash and do not matter just as long as the movement and breathing techniques do their very physical work on the human body.
The problem with presenting functional techniques as deeply linked with an esoteric philosophy, a religious movement or (in Tolle's case) a guru is that the technique is often used as a token hook just to lure the person to follow the movement or philosophy.