Should one distinguish between meta-thinking and meta-meta-thinking?
I think not. I feel that it would be reasonable to define meta-thinking as "thinking about patterns of thought", with the content of these lower-level thoughts having no particular importance. They could be object-level thoughts or meta-level thoughts; in either case reflecting on their patterns would be considered meta-thinking.
This also fits my experience with meta-thinking skills on LW. I've found that techniques like Hug the Query can be applied regardless of the current level of abstraction.
When do you go meta? When do you stop going meta?
In the video Q and A Eliezer offered some advice about this (the emphasis is mine):
In his discussion post "Are you doing what you should be doing?", Will_Newsome identified what seems to be an important guiding principle of meta-thinking:
(where "time-saving results" can be replaced with "greater marginal utility" to obtain a form that is more generally applicable)
Some questions we could explore:
(I plan to try to compile the insights and advice here into a top-level post discussing the principles of, and heuristics for, effective meta-level thinking)
Edit: Changed minor wording and altered the third question posed.