The current advice being given to, "think outside the box" has not noticeably changed the way the vast majority of people think, as far as I can determine. The primary reason for this is that the puzzle presented by the injunction to, "think outside the box" cannot be solved without understanding that, The Box is made up our personal Belief System.
Our personal Belief System is what the vast majority of individuals think with, and what shapes their day-to-day behavior. They, one, do not know that they have a "Belief System"; two, aren't aware of how they developed it; and, three, if he or she decided to explore it, haven't the vaguest idea of how to begin.
When born, and even before, an individual begins to build the System through what they experience with their Awareness/Sensory System--their environment. The Awareness System is primarily what we experience with: hearing, seeing, feeling, smelling and tasting. Additionally, everyone is born with an, unexplored, ability to sense things in other ways; sometimes called our "Sixth Sense," for some it is, "intuition."
In short order, the individuals who make up our family-group begin to Program us in many ways with what are, essentially, their Belief System, which shape their day-to-day behavior and interactions.
Their developed basic Belief Systems, generally, are made up of: the culture/social-group(s) with which they identify, which may or may not include their religious affiliations, and/or racial identification. The more the members of the family group share these affiliations, the more unified the Programming the child takes in, in these areas, will be. The less cohesive, the less likely the growing child will closely identify, and, thus, be totally Programmed by conflicting systems.
As one grows older, Indoctrination is added to ones Programming, through various educational systems; primarily the schools attended. All educational material is presented in the officially- sanctioned schools as given Facts/Truth. Our earliest education is primarily made up of what come to be basic building blocks: social skills, behavioral expectations, expanding relationships, etc., etc. Increasingly, learning skills will be added; reading, writing, arithmetic, etc.; along with, and after that, different subjects will be introduced.
Over the years we acquire vast amounts of information, which we have been Indoctrinated to accept without questioning its accuracy. (Why were you required to memorize and regurgitate all of what you were taught, if it wasn't True?) The more, "educated" we become, the more we begin to identify with what we are Indoctrinated to believe in is, "knowledge," i.e., True. The more, "advanced" and "specialized" the education we obtain, the more we are likely to have become identified with it.
The same kind of Programming goes on throughout our whole lives as to what is, or is not, "Reality." If we, early on, suspect that what we are expected to believe is, "reality" is not, "all there is to it," due to having had personal experiences which conflict with that view of reality, will try to resist this early Programming. You are probably familiar with the phrase, "Resistance is futile"; in actuality, it is practically impossible to resist the Programming/Indoctrination to which you have been exposed. When still young, most stop resisting in order to, "fit in" with their social groups. The subliminal social Programming to be, "normal"; or, at minimum, be able to pass as, "normal" is immense.
All of this is what makes up the boxes within which the vast majority of individuals think and live their lives.
Many think they have put aside early childhood Programming, by taking on the new Programming/Indoctrination gained through, "getting an education." It doesn't matter whether it was a, "good education" or a, "poor education" it was Programming/Indoctrination in the Consensus Belief Systems.
The first step required to begin to, "think outside the box," is to try to stop identifying with all of it, and to start questioning what you take in daily, in any shape or form. Most of what is contained in our Belief Systems we believe to be: Facts, Truth, Reality. The best way, I think, is to do your best to shift Everything you Believe, (think you know) into a category of, "as if true."
If you can successfully do this, you will be somewhat more open to considering conflicting information as it comes in, as opposed to dismissing it "out-of-hand."
A way of weakening the hold our Programming/Indoctrination has on each of us, is to search out, and investigate other, conflicting, material, and compare them, non-judgmentally; preferably any and all other systems you can locate. It is more practical to select one area at a time, as, once you start De-programming yourself, you are likely to find that it is not unlike being on a ship that is breaking apart. There is a tremendous amount of alternative information available, if you are willing, and brave enough. to explore, "outside the box."
My self-educational background has been in learning, and writing about, why people do what they do. My educational background includes the study of established Belief Systems in the field of Psychology, ranging from Freudian theory through Abraham Maslow's work on fully-functioning individuals, as well as Art. My BA is in Human Services, and my Masters is in Art Therapy--MA-AT.
In the 1970's I wrote a manuscript, (unpublished) called: You in the Process of Becoming; A Guide to the Self. In it I outlined a systems approach to understanding human behavioral dis-functioning. My current writing and thinking is an outgrowth of the understanding that, if an individual wishes to be able to think, "critically," i.e., originally, clearly and without contamination from Consensus Belief Systems, it is essential for that individual to thoroughly understand their own underlying Belief System.
This approach can be used in understanding an individual's problems in dealing with everyday situations and problems in relationships. In discovering how one's underlying beliefs shape personal behavior, and examining where those beliefs came from, can do much to change the resultant behavior.
You can access my blog at http://www.ruminationsonresponsibilities.blogspot.com/