I'm convinced of my own cluelessness, especially since I hold enthusiastic but loose & agile positions on everything on principle. But I do follow a lot of great speakers and writers with a gift for sharing inspiring and useful ideas. Our modern epidemic of self-help gurus & life coaches notwithstanding, I think there's some real wisdom out there as signal amidst the noise.
Some of the people whose words I enjoy for their useful insight tend to be in business (Seth Godin, Paul Graham, Gary Vaynerchuk, James Altucher, Warren Buffett to name a few off the top of my head), personal growth (Steve Pavlina, Steven Pressfield, Danielle LaPorte, Cal Newport), and spirituality (Martha Beck, Tara Brach, Eckhart Tolle, Charles Eisenstein).
This begs a key question: what is wisdom? From years of observation, here's my take.
Wisdom is the synthesis of knowledge into insight.
To gain wisdom is fundamentally a practice of accurate pattern recognition: you are faced with input (facts, experiences) and you apply awareness and analysis to tease out the insights, a distillation of value from volume.
The other characteristic of wisdom, besides that it is derivative from fact and the outcome of an actively intellectual practice, is that it's useful. By its very nature, it takes input and converts it to insight that can then be applied to relevant future scenarios.
You have situations A, B, and C. They all have X in common, which allows you to generate insight Q. You then are faced with scenarios D, E, F and notice that they also exhibit signs of the pattern X. You extrapolate, apply Q, and are able to take some shortcut to more efficiently think about or do whatever those scenarios require, this time with better external outcome or with a smoother internal (mental, emotional) experience.
In short: find patterns, generate insights, do better. And maybe even live a little happier as a result, as life becomes faster and easier over time.
If human personalities fall into archetypes, and I believe they do, I'm a hardcore perceiver and thinker (if you couldn't tell). So I try to apply this process to my life at all times, in both the inward and outward directions. I'm both a deep-sea diver of my own psyche, exploring my inner workings with the zeal of a scientist set out to disprove or prove a hypothesis, and I'm a keen analyzer of the world, constantly studying humans, societies, and businesses to find the core insights hidden in the seeming chaos of cause & effect. This process also involves consuming the wisdom of others to iterate my own constructed models of understanding, which is an efficient and personally enjoyable way for me to optimize the optimization process. ;-)
In other words, I like hacking life. Finding better ways to do things is extremely gratifying for me, and I especially like to apply this process to the inner human emotional-psychological landscape, because I think it's harder to study but just as replete with interesting patterns awaiting discovery.
But while hacking your biology, your startup, or your social life are more straightforward processes with more tangible moving parts, the process of hacking your own thoughts & feelings is definitely more parts art than science, and often this constitutes the core of wisdom. It involves a finely-tuned sense of awareness being applied to how we think, feel, decide, and relate. It also tends to require more patience, I think, since becoming a baseline happier person with patterns of thought and feeling that serve you instead of obstructing your life experience and goal attainment is fundamentally tricky.
Living life with skill—that is, with the maximum net love and happiness, which we fundamentally seek—requires knowing how to think, feel, decide, and relate better. And this demands an inward gaze towards our own nature, a constant (and compassionate) study of what we're doing and how we can do it better.
There are ways to strengthen the pattern recognition muscle (meditation comes to mind), but I think starting with the intent is enough. And always being open to the lessons that are there is another key, especially when faced with undesirable outcomes. Given an existing scenario, to persistently react with negative emotion or thought is futile and self-defeating. Instead, to maintain a constant mentality of learning, I've found, is the best way to always get the most out of life. In this orientation of receptiveness to feedback, no negative experience is a source of regret, nothing is without its lesson, and everything becomes progress towards a more accurate model and system of living. This, I think, is the art of living skillfully.