Any sort of meditation such as open-eyed Zen sitting or Vajrayana Shi-Ne hones the ability to observe. An OODA loop is an action loop consisting of Observation, Orientation, Decision, and Action. The latter three all depend on a clear awareness, to take in as much data as possible for the resulting action.

Mindfulness can be thought of as a scaling of meditation, providing a framework that a large collective can distribute and assess. This is the difference¹ between an animistic dance calling to the spirits and a hymn recital. One is spontaneous, clearly impossible to replicate. The other is designed to replicate, like pretty boxes filling out flattened land in suburbia. Each has its place.

Given that OODA loops are themselves a scaling device for behavior[^acro], they can be paired with the mindfulness version of what uncluttered observation techniques grant. Namely, RAIN:

Recognize what is.
Accept everything just as it is.
Investigate with a curious, caring touch.
Naturally aware, without identifying with whatever is.

Recognize and Accept fall neatly under ‘Observe’. Investigation falls under ‘Orient’. Maintaining a Natural awareness is also under ‘Orient’, to prepare for a more information-rich² decision.