Practice
In my personal practice, I do several types of mental training, which I loosely categorize into three bins. (Disclaimer: My perspective on these techniques is idiosyncratic, so take their descriptions with a grain of salt. Moreover, these techniques have often not been developed with an orientation towards rigorous science or careful experimentation, so take their utility with salt to taste.)
Mindfulness approaches
I got my start in mindfulness techniques with a practice called relational meditation (or
"circling"). Relational meditation takes a classic
mindfulness orientation -- purposeful direction of non-judgmental attention towards present-moment experience -- and applies it to active social interactions. So instead of meditating quietly alone, you're meditating while in conversation with another person (who is also meditating), and talking about what's happening internally as you interact. I became a facilitator of this technique and ran workshops on it for a while.
From relational meditation, I jumped into more classical meditation, started meditating daily by myself, and spent two months living at a
secular monastery with Zen Buddhist roots.
Somatic awareness approaches
Through my meditation experience, I became interested in a related set of approaches that I call "somatic awareness" techniques. Psychologists are likely familiar with the idea of
"somatic markers": that important decision-relevant information can be
encoded in somatic signals like skin conductance or muscle contraction. The claim behind
somatic awareness approaches to introspection training is that these signals are happening continuously, can be high-dimensional and richly informative, and, through practice, can be increasingly brought into conscious awareness. The technique that I have explored the most in this space is called
"focusing".
Rationalist approaches
Finally, I have been heavily influenced by a third set of approaches that I call "rationalist" approaches. What unites these is that they draw explicitly from experimental psychology and analytic philosophy, and they adopt a relatively more scientific mindset; although they don't run full-blown randomized controlled experiments, they rely on careful reasoning, self-critique, and informal experimentation to develop their methods. In this space, I have been influenced by techniques developed by
Leverage Research (in particular "belief reporting"), the
Center for Applied Rationality (see their
handbook), and
Joe Edelman's work (including the
Future Togetherness Test Kitchen).