Andrea Kuszewski, a behaviour therapist, has come up with five rules of life, that if followed, will "maximise your cognitive potential". Basically, make give your brain more wrinkles. Luckily, you guys are probably living like this already.
Kuszewski isn't talking about improving crystallized information—memory training, remembering facts, etc—but talking about fluid intelligence—the capacity to learn new info, retain it and then use it as a foundation to solve the next problem. In order to improve that type of intelligence, she suggest you:
1. Seek Novelty
2. Challenge Yourself
3. Think Creatively
4. Do Things The Hard Way
Maybe you think her advice is a little hokey, but I can't say I disagree with her. As Kuszewski says it: trying new things triggers dopamine which keeps your brain juiced and engaged, challenging yourself keeps your brain from getting lazy, thinking creatively is more useful than memorizing facts, doing things the hard way exercises your brain and networking makes the other four steps easier. Even if you don't think improving your intelligence is as simple as living life by those tenets, her essay at Scientific American is well worth a read. [Scientific American]