There are ways to get smarter in certain ways. What I think is most productive is to learn how to use what you've got.
Here are a few ways to try to improve your brain directly, rather than just learning how to use it. I tend to be a bit skeptical of brain-training type approaches because you have to be aware of the surprising specificity that comes in the improvements associated with practicing most tasks. But with that disclaimer out of the way, here are a few interesting things to consider.
Exercise is one of the most important things you can do for your brain.
Here's an article about reasoning training:
http://blogs.scientificamerican.com...ctivity-associated-with-high-level-cognition/
Which makes me wonder how studying for the LSAT compares to doing math problems. The brain-connectivity is interesting, but I still wonder about skill transfer to other tasks. Still, it's good to be able to think logically, and there's a reason law schools want you to study for that exam.
It's also worth looking into meditation.
http://www.sciencedaily.com/releases/2010/04/100414184220.htm
So, those are the main ways to improve what you've got that are backed up by scientific studies.
I mentioned the benefits of practice tend to be very specific. That doesn't mean it can't be very powerful:
I downloaded a program that helps you to practice this mental abacus stuff, starting with mental addition. You could question the value of this when you can just use a calculator, versus a lot of training. But a calculator isn't as cool and impressive. Plus, part of my point here is that specific skills can be valuable, and if you have a narrow target skill, typically, all you need to do to become awesome at it is is lots and lots of practice! Some of these skills may allow you to build other more useful skills on top of them.
There are some other things that can help, like making sure you are not under prolonged, excessive stress in your life. The other thing is to figure out how to use what you have. To that end, you need to learn how to implant things in your long term memory. I will single out the most important things to keep in mind here.
1) Practice remembering, without looking at what you are trying to remember. When you read a paragraph, you can stop reading, step away from the book and try to summarize what you just read without looking.
2) Spaced repetition. Repeat 1) after 1 minute, 1 hour, 1 day, 1 week, 1 month, 1 year...don't take this too literally--experiment to see what works. Some tasks may need daily attention to improve performance, with less of the spacing.
http://en.wikipedia.org/wiki/Spacing_effect
3) Try to make things memorable. Visualize them if possible. The emotional aspects of learning are important. Don't see everything as just piles and piles of dry facts.
You can go and try to read more about how memory works. Those are just some of the main points. It turns out just about everyone has an incredible memory. It's just that most of us do not develop the skill to use it effectively. There is a whole world of memory techniques out there.
http://www.ted.com/talks/joshua_foer_feats_of_memory_anyone_can_do?language=en
One caveat with this type of stuff, though, is that it tends to be useful mainly for rote learning, rather than understanding. Rote learning does have its uses, but understanding is more valuable. However, I think knowing a little bit about it does give some insights into learning and memory more generally, which can indirectly have some bearing on improving your ability to understand and retain more conceptual material, as well.
There are ways of improving your ability to understand, as well. Practice is part of it, but also finding good examples and learning from people who give enlightening explanations, rather than people who like to just move symbols around. Moving symbols around violates principle (3) above and thus results in completely unmemorable explanations of things, although PRACTICING the symbol-moving and the rules can help internalize the necessary symbol-manipulation skills.
