Whenever I'm working on something concrete or specific, I attempt to turn it into more abstract claims and questions that I can generalize. When I've developed a more abstract claim, I search for more situations in which to apply it. I then adjust the mental model situationally, and ask if that requires my understanding of the abstract model to be adjusted as well. Repeat. This is a core process that I follow to apply learnings from behavioral science, game design, and past projects to present/future projects.
These abstractions can be found by asking yourself, "If I take out the specific details of this situation, what is the structure of what I just did?"
My favorite way to go up and down the ladder of abstraction is by making Lenses of behavioral science and game design principles for myself. Whenever I find (or come up with my own) frameworks, theories, or findings that I think could be abstracted beyond the present context, I turn them into "lenses." Each lens is a series of questions to ask myself in order to look at a problem through the lens of that concept. This is going up the ladder of abstraction.
To then go down the ladder, I need to apply that lens to a specific situation to see if it fits and adjust it accordingly.
Roam can enable this process through block and page references. To see a concrete example of this, here's a link to my public Roam with some instructions.