Earlier quoted context omitted.
There is a ton of research in this area and an entire field of clinical therapy called "cognitive behavioral therapy". There's literally too much to cite :-)
I did some googling around on the topic for past couple of hours. Seems like the jury is still out on it? This[1] article cites some research contradicting its past reliability. It seems too hard for a layman to make heads or tails of it. Let alone make recommendations to others, which seems irresponsible and dangerous to say the least. https://www.psychotherapynetworker.org/blog/details/705/is-c...
http://slatestarcodex.com/2015/07/16/cbt-in-the-water-supply...
http://slatestarcodex.com/2013/09/19/scientific-freud/
http://slatestarcodex.com/2015/07/13/things-that-sometimes-w...
http://slatestarcodex.com/tag/psychiatry/
I only read a couple of these and that was a while ago, but one interesting (and completely unproven) idea was that CBT's effect size could progressively vanish because so many of the useful ideas are being incorporated into folk psychology.
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There's a longer post that I'd like to write about this topic in general (CBT, mindfulness, thoughtful self-help à la the OP) that I'd like to write, but that's going to take more thought. So I'm just going to throw some notes down.
The conclusion I've reached is that you can take that same analytical lens you use to tackle technical topics, turn it inward, and get actual benefit for relatively little time invested.
Recently I read Your Brain at Work. There were some flaws (eg, it really pushed ego depletion, which has failed to replicate), but one idea that stuck with me is that mindfulness isn't just hippie "being present" stuff. The meditative exercises can feel like that, but there's also a very analytical reflective aspect. One benefit of meditation is that it makes you more conscious of your own thought processes, which allows you to notice and stop unwanted mental processes as they arise.
Some other recent essays made the point that the most important benefit of the quantified-self movement is reflection, and you should make your choices about what and how to track based on that.
http://www.ribbonfarm.com/2016/03/24/the-holy-grail-of-self-...
http://www.ribbonfarm.com/2016/04/21/a-framework-of-experime... (the section Concrete Reflexivity is the most relevant)
I've been working on some habits inspired by http://lesswrong.com/lw/fux/my_workflow/. What I found most valuable was incorporating periodic, deliberate reflection into a daily routine with a (digital, searchable, cross-referenceable) paper trail.
I realized that TODO lists weren't just useful for remembering to do things but also useful for clearing out mental static. So instead of just keeping lists for work/school, I also kept a list of more frivolous things (project ideas to flesh out, looking up peoples' opinions on some book, etc.) and would offload any distracting thoughts that came to mind during work hours to it.
I'd heard somewhere that speaking to someone in the morning helps you wake up faster, so I begin practicing Duolingo in bed on important mornings, and kept track of how long it took me to get to work each day (+how much sleep I'd gotten, etc.).
I'd been reading about Jonathan Haidt's theory of moral value and how a lot of human political instincts could be framed as extensions of the basic disgust instinct, so I decided to try deliberately linking distraction with uncleanliness in my mind. I don't think that was particularly helpful or harmful. But in the process I noticed that uncleanliness for me corresponds to a feeling of skin-tingling, like I hadn't showered for a day or two, and I did start having that same feeling when I was getting off-task during the day.
I'm not sure any of this has made me significantly more productive, but the sense of mental control has made me calmer.