It comes from a number of sources, both words you can read and experiential things. These were studied, experimented with (on myself), and practiced over the course of the last fifteen years. I have never attempted to synthesize what I am trying into a coherent whole, and I am still learning and assimilating other methods.
Neuro-linguistic programming is probably a good place to start. That's where you get ideas such as sensory modality, reframing, etc. I mostly went through a couple books transcribing John Grinder and Richard Bandler's workshops in my twenties. Grinder and Blander mentions Virginia Satir and Milton Erickson a lot. Grinder and Bandler was where I first learn to "chunk down" skills and ideas (in software engineering terms: to decompose a skill into micro-skills). NLP is where I also learned how to construct (and deconstruct) visualization exercises.
Other methods along these lines are Suzuette Haden Elgin's "Gentle Art of Verbal Self Defense", which has a lot of patterns and anti-patterns on use of words. I have read through Jay Heinrich's "Thank You For Arguing", which is the book I credited for making the distinction between being right and being persuasive for me. (Can't wait to start teaching my daughter Heinrich's material).
The most recent, more mainstream book I am working through is "Take Back Your Kids" by William J. Doherty. My wife found a condensed, one-page essay by Doherty on respect and community building and I started deep diving into his book. This one is important since my wife and I concluded that part of the issue with my daughter is that entitlement attitude was conflated and intertwined with the issues with the autism syndromes. We had already gone through the Intense World Theory, so we had a good feel for what was likely to be autism related ... and what was more likely to be entitlement.
The rest of this comes from experiential sources. There are good literature to start one off, but reading it alone will not lead to understanding. Experiencing it will.
The shaping and solidifying of intent comes from several sources converging together. Internal martial arts has a lot to say and practice about the shaping of intent. In particular: xingyiquan emphasizes when intent clashes together; taijiquan emphasizes the relationship and the give-and-take of intent between two people; and baguazhang emphasizes the changes that take place within a person as a result of changes in the environment (and how intent plays, shapes, and is shaped by the environment). I have not even begun to scratch the surface of these arts. I've touched it just enough to know, there are some broad and deep healing applications when it comes to people.
Shamanic practices has a lot to say and practice about the shaping of intent as well.
Mindfulness practices lets you get a sense of ebbs and flows of sensations, emotions, and thoughts. It is entering that stillness and emptiness that lets me try all these different techniques, and to observe what is going on.
One interesting phenomena happens after becoming sufficiently mindful: you become aware that some of the shifts and changes in your own emotions and thoughts are actually mirrored in the other person. It becomes hard to say whether it is "your" thought or the "other person's" thoughts.
This perspective has been very useful when working with my daughter. At first, it was hard not to get caught up in what she is thinking. After a while, I started recognizing when she was getting in stuck patterns, loops; whether because she was drawing a complete blank, or because what I said was too ambiguous for her, leading her to fan-out into many possibilities. I can also tell when she "skips" steps in her thoughts, and because it happens so fast for her, it doesn't even register as a conscious thought for her (this is the part that a lot of people mistake as an expression of ADD).
Right now, my daughter controls her mind like the way an overeager and anxious teenager drives a car. She doesn't know how to adjust the accelerator and brakes, doesn't know what "enough" means. All she knows is to push things to the metal. Asking her to remember and to introspect on specific thoughts and feelings is like asking her to park the car at one specific parking spot in a busy parking lot. Without the ability to adjust how much to push on the accelerator or to break, it is hard to refine movement of the car and get it into the parking space. You're going to run over a lot of things. Likewise, when she retrieves information, when she processes emotions, when she tries to reason through things, she slams on the accelerator or slams on the breaks. She jerks her mental steering wheel and then overcompensates when trying to correct it. (And she does that physically with her bike; it took practice before she started to figure out how to gently squeeze on the breaks to control speed). She has a powerful mind, but lack control and wisdom.
It's my belief that this skill is learnable and trainable. I did the same with my own thoughts and intent, and it took practice to work with it more gently and more subtly. It requires a sufficient level of concentration and mindfulness. It requires knowing how much is enough intent, and to watch for the results that comes from expressing or executing that intent.
Hope that helps.