(this is a rough sketch based on my research, which involves reviewing cognition enhancement literature)
Improving cognitive abilities can be done in a variety of ways, from excercise to drugs to computer games to asking clever people. The core question one should always ask is: what is my bottleneck? Usually there are a few faculties or traits that limit us the most, and these are the ones that ought to be dealt with first. Getting a better memory is useless if the real problem is lack of attention or the wrong priorities.
Training working memory using suitable software is probably one of the most useful enhancers around right now - cheap, safe, effect on core competencies.
When it comes to enhancement drugs, my top recommendations are: 1) sugar, 2) caffeine, 3) modafinil (and then comes a long list of other enhancers). Sugar is useful because it is effective, safe, legal and has well understood side effects. Just identify your optimum level and find a way of maintaining it (this requires training one's self-monitoring skills, always useful). For all drugs, there is a degree of personal variability one has to understand. Caffeine is similar, and mainly useful for reducing tiredness ...
As I remarked in another comment, exercise has documented effect. It is rational to do not just for health but for cognition (so why don't I exercise?
Well, why don't you? And everyone else who complains about their "somehow" not exercising. It's a common complaint, even here on LW, where one might expect people to have already risen above such elementary failures of rationality.
This is not a rhetorical question. I speak as someone who does exercise, as a matter of course, every day, and have done for my entire adult life. (Before then, I wasn't averse to exercise, I just didn't give it much attention.) So I do not know what it is like, to not be this person.
So, what is it like, to be someone who thinks they should be doing that, but doesn't? What is going on when you see in front of you the choice to bike to work, to do 20 press-ups right now, to get a set of dumbbells and use them every day, or whatever -- and then not even click the "No" button on the dialog floating in the air in front of you, but just turn away from the choice?
Likewise, every other actual practice that you think would be a good thing for you to do. If you think that, and you are not doing it, why?
Calling it akrasia looks like a way of getting to not fix it.
Jaeggi and Buschkuehl's dual n-back task has been shown to improve fluid intelligence. Citation, Wikipedia, online implementation.
If you're interested in cognitive drugs, the first thing to do is to have a community effort in which everybody pays to have a microarray detect their SNPs and repeat counts, and then experiments with different drugs, and reports the results and links them to the microarray results.
The NIH is paying for a large genotyping experiment, but they're not recording phenotype data, so the results will a) be mostly useless, and b) deter anyone from allocating the money to gather useful data anytime soon.
Okay; increasing IQ is, where possible at all, very difficult.
What other, perhaps more specific, cognitive skills with practical value could we try to enhance? A lot of debiasing techniques discussed before fall in this category, but in very narrow ranges of application.
Other cognitive skills are more general-purpose. For instance, are there any known, tested means of improving recall from long-term memory, or improving cognitive focus?
If improving general intelligence is difficult, let's go for any low-hanging fruit first.
I like the staples - they all have their role to play in pushing the brain where you want it to go. Caffeine enhances concentration - my understanding is that continual small does (e.g. drink tea all day) are better than one big hit.
Alcohol mitigates biases against socially acceptable ideas by reducing inhibition. Think spirited debate over a pint, not all night bender. I find I am more receptive to odd ideas after a couple of beers.
THC (the main active agent in marijuana) is good for flashes of inspiration. I find my software designs when baked are brilli...
I take ritalin and a single cup of coffee most days. Physical exercise is supposedly helpful as well.
Research on short-term intelligence test result modifications by activity - by Kevin Warwick
Reading/Swatting -6
Listening to classical music -2
Watching a chat show on TV +5
Playing with a construction toy -4
Sitting/Chatting -2
Watching a documentary on TV +4
Walking +1
Meditating +2
Watching Friends on TV +1
Completing a crossword puzzle 0
Alcohol 0
Chocolate -2
Coffee +3
Orange Juice -2
Peanuts +1
Toast + Orange Juice +3
Bacon Sandwich +3
Control 0
Cereal -1
Eggs (various) -5
A bigger and better table would be ...
Education and computers seem like the big ones to me. For education, see the internet. For computer-based intelligence augmentation, I have an essay on that, here:
Transhumanists have high hopes for enhancing human cognitive abilities in the future. But what realistic steps can we take to enhance them now? On the one hand Flynn effect suggests IQ (which is a major factor in human cognition) can be increased a lot with current technology, on the other hand review of existing drugs seems rather pessimistic - they seem to have minor positive effect on low performers, and very little effect on high performers, what means they're mostly of therapeutic not enhancing use.
So, fellow rationalists, how can we enhance our cognition now? Solid research especially welcome, but consistent anecdotal evidence is also welcome.