For me, it's been a gradual process. I started by - and still need to be - observing all the times that what I thought about (pleasant or unpleasant) came into my experience, recording in some way each incident, and practicing observing it as it happens. We often refer to such incidents as synchronicities.
Then I started managing my thoughts, so what I focus on is what I want more of, canceling or erasing any other kind of thought (and yes, I'm still practicing at that one too :) I focus on the qualities, the characteristics, not the form, as in mutually supportive relationships, comfortable home, easy transportation.
AND I sing songs and read texts that support my understanding that the universe is, in fact, as Wallace Wattles says, supporting and supplying my needs and desires, which helps me remember that truth while living in a culture that's designed to operate in contradiction with it.
I trust that my having worked through it makes it easier (and faster) for others to do so.
Blessings on the journey!