In the development of the path of insight (whatever that means to you), it can be very helpful to discover (or construct if you have to) personal ‘signs’, ‘road-markers’, or ‘fingerprints’ of certain types of qualia (the sense of the experience of something: the felt sense of a certain types of mental state). Ideally, these can be like ‘meta-labels’ within the practice of vipassana and can be used to guide through the emergent stages of meditation.
These can only be constructed or discovered in retrospect… if one sees the impermanence of all mental-material phenomena through momentary concentration of noting the arising and passing objects of experience, the characteristics of that state of mind (its qualia) can be ‘tagged’ as having a certain quality; a certain ‘felt sense’…
Learn what it feels like to feel in that state. Know what it feels like to ‘know the arising and passing nature of…’ and allow that knowledge (of a perceptual-cognitive nature) to organize mindful efforts during the practice – only to the “extent necessary for bare knowledge and continuous Mindfulness” (see Satipatthana…).
Prepare the practice of living during (object-oriented) open-monitoring insight meditation by seeing when things are clearly seen; through momentary concentration, the fingerprint or distinguishing marks of those passing states of mind will aid in the building of mindful and penetrative observational dispositions.
This skill is essentially an understanding and manipulation of the faculty of sense perception (as opposed to the cognitive function of perception to recognize, mark, organize, etc): bare awareness -> appraising-organizing of feeling-perception -> representative thought -> mental proliferation (the train of thought).
Knowing this conditional process is to know the location of the door to freedom from unskillful patterns of relating to experience, and recognizing the qualia of seeing the nature of mental-material phenomenal interaction begins to guide us to that door.