This will be short and to the point.
Sometimes when you are learning something, you reach a point when you are constrained by raw power. Think physics and particle accelerators.
You compensate by being better at interpreting subtle evidence. Even with low power, you can learn most of anything if you have good models, and do the hard work of extracting a weak signal from noise.
However if you find yourself in this situation, increasing power should be your first priority. If you hit the power jackpot, you'll experience some very rapid progress, because your sophistication is way ahead of your previous level of power. You are ready to wield more of it.
To put it another way, when your actions have consequences, and you want to learn how to act, you should be throttling yourself on purpose. If you don't have to do it, then something is very wrong.
Human beings by default imagine that their conscious thought has more influence than it really has. They think it because they are fooled by their brain's built-in biases.
The first correction is to note how little control we really have over anything, aka the "rider and elephant". After realizing this, you can make good use of whatever little power you have. People from rationality/LessWrong circles tend to get this right.
So at this point it should be clear that the conscious mind/System 2 operates in a sort of a sandbox.
The second correction is to realize that you can go out of the sandbox. Of course, the keys to exit the sandbox are weird-shaped, and require work to acquire. They must be like this. The point of a sandbox is that you shouldn't be able to exit it by chance.
However, rationalists are more than ready (at least some of them!). The problem is that they also tend to believe that the sandbox is the whole world, and they do not seek the keys.
A part of the reason seems as simple as: it's low status to say that conscious thought has superpowers inside of the brain. That's what people think before they make the first correction.
Putting 1 and 2 together. If you are ready, seek power within your mind, because the power is there.
By the way, if you go to a long meditation retreat that does not suck, they can probably teach you enough. It will be unpleasant, because their methods are crude and their models are crap. But you only need to stick around for long enough to see that the power is real.
You also need to not bend your neck to the power, and worship it just like millions of people did over millenia. Reductionism! Consequentialism! Bayes! These are powerful tools, use them! You'll figure it out, because you are ready.
Update: In case you are wondering just what kinds of things are possible to discover outside of the "sandbox", here's one example about which I wrote recently (added only to satisfy your curiosity, it is not presented well enough to convince you of anything).