Our never-ending excuse making for ourselves is miraculously somewhat closer to correct than our evaluating the causes of others' actions, though it may be systematically untrue in the opposite way. We don't understand others' decision making, but we don't naturally understand our own either.

Can you clarify what you mean here? Right now, all I read from it is "We have a slightly greater probability of correctly identifying our own actions than we do those of an outside observer." While that may be correct in some cases, it actually seems to contradict the the focus of the text:

These studies suggest that people do not have introspective awareness to the processes that generate their behavior. They guess their preferences, justifications, and beliefs by inferring the most plausible rationale for their observed behavior, but are unable to make these guesses qualitatively better than outside observers.

Concerning this statement:

Less wrong thought needs to be part of the entire process - it needs to guide the entire planning stage, not just the thoughts in it.

If decision making begins before conscious thought, and is "greatly influenced by the most mundane and irrelevant things", and the conscious portion of the brain is the only part we have to work with in planned, rational decision making (at least consistently- learned, rational habits not withstanding), then it would follow that a first step before we take action would be to review the action we are about to take and make sure it lines up with rational thought- since we know our brain will attempt to explain why it is taking the action independent of the actual cause, only by ensuring the action is rational before we take it can we keep from undercutting ourselves as we attempt to accomplish our goals.