In my experience, the vast majority of advice is either too vague or too trivial.
But sometimes you stumble upon magic. Stuff like Anki. Or HIIT.
Can I take this opportunity to ask about HIIT? What kind of HIIT workout do you recommend? I ask because you're putting it on the same plane as Anki, so it must be truly amazing.
At present time, I do 12 sets of 20 seconds work and 20 seconds rest, alternating between push-ups and squats (2 set of squats, 1 of push-ups). When I started, a bit more than a year ago, I did 6 sets. I average 14 squats and 12 push-ups in a set. 20/20 is different from the Tabata protocol, which advocates 20/10, but I found that one too hard. I may start lowering the rest time at some point.
HIIT is amazing for me in a sense that, just like Anki, it became a habit I enjoy doing (~3 times a week) AND it led to a significant body changes (less fat, more muscle).
For the record, I have to note some confounders:
During the time I began HIIT, I also gradually changed my diet. Nothing fancy, I just lowered the amount of carbohydrates I eat by cutting down bread and pasta and stopping putting sugar in my coffee.
I don't only do HIIT. After HIIT, which takes about 15 minutes, including stretches, I also do some core exercises (planks, bird-dogs, glut-bridges, leg-raises etc.). Those take another 20-30 minutes. The advantage of the whole thing is that I can do it in my room, no hassle of going to the gym required.
To conclude, I can't say that I recommend this workout for some deep reasons. I just found something that worked for me. You are free to try.
Another benefit of writing insights down is that people are prone to reverting to their old System 1 habits and letting their System 2 forget them. As per Pavlov, it usually takes quite a few tries to internalize an insight, and having stuff written down helps fight the reversal long enough to get a new habit established. The "share with the world" bit may or may not help, but it is usually cheap, so why not.
I like this idea, and I'll post if I can get around to it over the weekend.
In the past I've used https://thoughtback.com to send me quotes,ideas and maxims I thought useful. These come up at semi random times in email, and retriggers the memory and context - probably not as good as Anki, but I enjoy having these show up in my email stream.
I have implemented this idea using Anki. A benefit of this implementation is that, instead of being exposed to the insights at semi-random times, you get to see them more or less often depending on past ratings.
I also enter insights into Anki, though sometimes it leads to "wait a minute ... in retrospect, that was kinda wrong."
That makes sense, I however try to keep my new cards low as I'm mostly bulking academic content and vocabularies. I still recall the first month with Anki, where the planning fallacy had me learn so many new cards that I was stuck within 2 weeks with something like a 2 hour deck, which then luckily eased off to a more sensible 35 minute deck I could squeeze in to my day.
How about rabidly deleting things you think aren't that useful? I feel good about deleting stuff in Anki, because I tell myself it's a good habit to have.
I do this often, and over time. I've noticed quite a bit of digital pack rat genetics in myself, not just related to Anki but data in general. Over this December holiday I reindexed and cleared out over 16 years of digital projects, I was amazed at the amount of things I thought I'd have use for again at some point.
What was however fun, was seeing how I've grown as a programmer and developer.
With Anki, I do it gladly, every note deleted with no practical value, saves me first the cognitive overhead and stress of review and second all those wasted little future times. With things like Coursera material, I've found that some information loses it value for me over time, so I might keep a personal note deck then, but export it, if I wanted to glance over it in future.
That's what twitters, tumblers, blogs, articles and books are about, more or less, as far as I'm concerned.
IMO, blogs, articles and books are too high-effort to start. You write a blog if you have an active urge to share your thoughts with the world. The point of a learnt.txt file like described is that you can start it for, effectively, zero cost in initiative.
Sharing what I find to be obvious and is my own internalized "common sense" is a philanthropic donation of the mind that for many years I was too selfish to be able to do. I personally have benefitted from the perusal of many blogs, finding help for both my personal and professional life and finally have come to accept that to give back to the minds around me will benefit myself and everyone else which will in turn benefit myself. I will throw out this tidbit of discovery now... Greatness is a function of effort. Huge projects that dwarf all before it are not greater than the smallest project of one careful person's craft.
Say you have just realized something that seems, in hindsight, pretty obvious - but that you were totally unaware of before now. You scratch your head, update your model of the world, and move on.
Hold on. Update your model of your model. Why were you not aware of it before? If this insight, in retrospect, seems so basic, then why did you not realize it earlier? And how many other people do you think missed it as well?
There is a common situation in user interface development, where you've written a marvellous, clear, easy to use piece of software - after all, you have no problems with it at all! You've stuck to the practice of dogfooding ("eat your own dog food" - use your own tool in day to day life) like a good developer should and are now quite faster in it than in whatever you were using before. So find a random coworker who has never touched your software before and may only be passingly familiar with the subject matter. Put him in front of your shiny user interface and watch him waddle around, dumbstruck and befuddled, as he misses all the obvious interface elements and tries nonworking things you'd never attempted in a hundred years. Resist your urge to correct him - pay attention to what he tries.
You cannot judge the obviousness of an idea from the inside - you have to find somebody without prior exposure and observe them attempt to come to terms with it, to understand. And it only works once - after he's become familiar with your idioms, he'll never be able to show this bright-eyed naiveté again.
If you're trying to write a FAQ for life, it'd be very much helpful to have such a coworker go over your life, re-learn all your lessons, all the insights you now consider obvious, and highlight them so you could add them to the help file. But of course, we cannot relive a life. We can only live it once.
So the obvious thing to do is when you realize that you've just had a novel realization - no matter how apparently trivial - is write it down. The brain is really good at caching - realizations become thought habits frighteningly fast. So write it down, so you don't forget that you once had no idea. And after you've written it down (probably on a file on your PC), why not share this file with the world? Might as well let others profit from your insights.
I think it would be useful to spread this habit. Imagine: somebody just did something really clever that raised your estimate of their competence, and oh hey, his user page has a link to a list of insights, maybe I can skip having to manually learn some of those myself? And look, the first piece of advice - "write down your insights", that sounds like a good idea!
It's not proven that this would be useful. But it costs little to start.
So here's mine so far.