On the plethora of Therapeutic modalities. 
There's a genre of book that's the therapy modality book. They're all the same. They go
I was a therapist and what I was doing wasn't working, and then I discovered <specific technique the book is advocating> and then it cured me and all my clients and now things are great and we just need to teach everybody this technique.
So many therapy books are like this. Focussing, the IFS book, the EFT book, to name a few. The various ACT books. Waking the Tiger.
And the specific technique is different from book to book. Radically different. And even contradictory.
So what's going on here? Apart from probably there's some book somewhere about how to write a therapy book, or some ghostwriter that's cranking these out?
If we take these stories as more or less true, how do we make sense of these seeming contradictions?
This is not a rhetorical question! I'm going to give you my best guess below, but please take a moment to think of your answer, and ideally post it in the comments for everyone to see. I am very much interested in other answers here.
Ok, my best guess (at least, the guess that I find most interesting):
What works is having a therapist who believes they are helping. It's like the placebo effect. If the doctor handing you a sugar pill is like "Yeah, idk, people told me this is helpful. lmk what you think", my guess is, you're not going to get much placebo effect out of that pill (actually they've done research and you do still get some but not as much iirc).
So when the therapist is out of school, they're doing what they were told works, but for a certain kind of mind, that doesn't give them confidence. So then they have to go on a big heroes journey, and come back with some technique, some approach, that for whatever reason they believe in.
Now they're back, and they believe it works, and low and behold, it does!
It's like Dumbo's magic feather.
"some technique, some approach, that for whatever reason they believe in."
So why do they believe in the technique they chose? Because they love to do it. Because, when they're doing it, they feel most like themselves, and they feel most connected with the person they're working with. Or they feel most connected with what they consider important, about a mind, about a heart, about a life.
And maybe this gives it some extra sauce too. Maybe this love of themselves, this intrinsic interest, radiates out, and reminds their clients that they too can love themselves, love life, be enthusiastic, and intrinsically interested.
Or maybe that last part is just what I have come to believe works ;)