To make thinking useful, it needs to be accumulative, because only something accumulative can make a path.
Not just any accumulation or any path will do, of course, but only the person doing the thinking can make those choices. How to think (not what to think) is to deeply experience your own thought, because if you experience your own thought it stays with you. Experiencing your own thought is like composting your garden, building a soil of rich material for future use. Logic, judgment, insight, even compassion and curiosity, almost all the mental 'chops' we start life being in awe of in others, come later.
The hard toil normally connected with pushing the brain to function better (booking it, etc.) is far from useless, but it's not 'thinking'. Only experiencing your own thought, connecting your mental world with your personal adventure of existence, begins working the world inside and out together to give you true knowledge. So, put the book down occasionally, and drink in the experience of the ideas it generates for yourself. The intellect needs to be fully heard by your heart and other levels of deep body awareness, or you ideas don't get digested and made part of you.
Honor your own beliefs and passions, not to freeze them in time, but as the sails and rudders that will take you on great journeys of becoming someone new. All the riches of life are out along a path of exploration you can get to only by taking every step. If deep experience connects your body, heart and mind, they can take you there together, each informing the other. If they're not connected, though, thought has little foundation and the body and heart no way to see.
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I talk a lot about 'natural systems', well, because I found a way to deeply experience (make part of me) the complex systematic events that evolve within them, and fill the world around me. I highly recommend it, for lots of reasons. One is that we need to cure the world of many complex systematic diseases, and that requires knowledge of how nature works that is not yet a common part of our 'mother culture' and natural inheritance of understanding. Our culture has had blinders on for a very long time, to the point where we basically need to brush away our illusions and learn how to see all over again.
In a way the task appears treacherous, like pushing people out into the cold, asking them to leave the easy and free flowing 'dream world' of human existence, where the images of our minds are all powerful and absolute representations of the world around us. Seeing the flaws is a kind of threat, since living in a bubble of our own imaginings is who we are, and needing to connect with the physical truth of things outside our control is indeed a threat to that dream world's complete authority. What I'd propose is that we, as a species, will not survive if we don't somehow both leave that dream world of human existence, and also bring it along on the journey, whole and intact. Basically I think we can leave the egg without really harming it, and then just put it in our pocket to bring along. That way you'll have it handy, like a familiar and very full featured cell phone, for when you return to it with new things or go back to it for old ones. Then it aids rather than inhibits your exploration of a more true and whole relation with the unexpectedly rich and physically beautiful real world in which we find ourselves.
The object of exploring the physical truth of things this way is not to cover up or erase one 'myth' with another, as is usually taught, but to enrich both. The connector is closely watching how your own dreams develop, as a means for introducing you to new levels of the magical truth of physical things. The physical levels of order in natural systems are expressions of independent self-organizing complex beings, a great deal more like dreams than numbers. The relevance of the extra layers of fantasy we overlay on them comes from our finding a tension and continuity between our own dreams and the physically real layers of complex order in natural things themselves. You choose which to bring into focus. It's also the way to slip into and out of the dream world of human isolation without breaking its shell. You just grab the 'hook'.
The 'hook' is the feeling of excitement you get in watching things grow, and then learning with experience how to read the signs of what is emerging from within. That's the way to tell when things are happening 'out of control' and nature is bursting on the scene with a whole new design, simply learning to notice the tell tale signs of things multiplying. If what you find directly connecting to those hints of something new is not the actual beating heart of an new emerging self-organizing network and environment, then it is very very close bye.
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How nature learns by exploratory learning is good to learn too... Life's hidden resources for learning published in Cosmos&History Sep 2008