Whatever our mind is thinking of, it is strengthening that concept. The stronger a certain concept is the more we tend to become such a person. So it is crucial to understand where we have our attention. These practices don't go into the best methods of changing attention but rather being aware of them. Even by being aware of our attention we subconciously start changing it.
Concepts; Being hydrated, my weight, housemates pretty friends, iq of people, mental-models, code, girl I like, Now I would rank them from most useful to least as.
This shows what I should accept more in my life and what I should avoid more. Ofcourse I use other mental models to order these and using different mental tools will help me order them in different ways.