I suffer from PTSD and I worked with my therapist on concrete things before I worked on the visualizations

for example

I would only listen to words, not try to find intent
so i repeated a lot of things to people
it kept my mind present instead of racing onto the next imagined thing

Like...I would hear somebody say something that I FELT was yelling or negative against me and so I would restate it ina question "what I heard you saying there was that you were really mad at me for breaking the glass" so that they could respond with their REAL emotions instead of the ones I was placing on them "No I wasn't mad at you for breaking the glass...I was worried you hurt yourself, are you OK"

once I was comfortablish (because I feel like a tool doing it now even though I know it helps all of us so I am never COMFORTABLE, you know) then I worked on visualizing how I wanted to feel and where I wanted to be.

I read the book the secret and worked really hard at stopping negative thoughts and phrasing things in different ways
so instead of saying
I won't get fired
I said
I WILL stay employed

the meaning is the same but one has negative words and one has positive words, if that makes sense

once you start using postive words it helps boost your mental attitude

I also got sick less and became healthier without actually doing anything different than changing negative words to positive ones

I won't have to walk far
to
I will be close to where I need to be