Exercise: Find at least one thing which you do for less than perfectly noble reasons, which you are going to admit to everyone else in the study group, and not fix for at least a week. Everyone else in the study group will admit something similar to you. Possibly followed by group hug. (The idea isn't that any given flaw is okay, the idea is that it's okay to have a running accurate description of yourself which involves known flaws you haven't fixed yet, and all of you are in that same boat together.)
Could you clarify somewhat what you mean by "less than perfectly noble reasons"? What I think of as "things I do for less than perfectly noble reasons" is an entirely different set than "flaws I haven't fixed yet". The latter implies consideration only of things that you can, should, and want to change. This is in contrast to things I do because I'm not perfectly noble and being perfectly noble is not a goal.
I actually think confessions and acceptance of both of those kinds of deviations from perfect nobility could be valuable. It's ok to have an accurate running description of how you are and also ok to have an accurate running description on how you want to be.
Recent brainstorming sessions at SIAI (with participants including Anna, Carl, Jasen, Divia, Will, Amy Willey, and Andrew Critch) have started to produce lists of rationality skills that we could potentially try to teach (at Rationality Boot Camp, at Less Wrong meetups, or similar venues). We've also been trying to break those skills down to the 5-second level (step 2) and come up with ideas for exercises that might teach them (step 3) although we haven't actually composed those exercises yet (step 4, where the actual work takes place).
The bulk of this post will mainly go into the comments, which I'll try to keep to the following format: A top-level comment is a major or minor skill to teach; upvote this comment if you think this skill should get priority in teaching. Sub-level comments describe 5-second subskills that go into this skill, and then third-level comments are ideas for exercises which could potentially train that 5-second skill. If anyone actually went to the work of composing a specific exercise people could run through, that would go to the fourth-level of commenting, I guess. For some major practicable arts with a known standard learning format like "Improv" or "Acting", I'll put the exercise at the top and guesses at which skills it might teach below. (And any plain old replies can go at any level.)
I probably won't be able to get to all of what we brainstormed today, so here's a PNG of the Freemind map that I generated during our session.