The most important catalyst for triggering Awakening to no-self is to investigate our Direct Experience. Direct Experience is what is noticed, here and now.
We can skilfully divide d.E., for the purposes of investigation, in to 3 main aspects:
feeling [tactile + kinesthetic)
3) an unmistakable sense of Aliveness
The illusion of separation is maintained by a stream of self referencing thoughts that are based on past conditioning. The most common reference point is a thought-created center referred to as "I" / "me" / "self". There is no such center, and those self-labels refer only to other thoughts, or to some aspect of Experience.
By referring to d.E., one is able to deconstruct any assumptions of separation or self, and see that there is just an Experience. There may be thoughts about Experience that conceptually divide certain aspects of Experience into a "me" and other aspects into "the outside world", yet those thoughts are also just a part of Experience, and as such there is ONLY Experience.
There is an assumption that there is an experience-er that experiences. This is propagated by a belief, as expressed by a thought such as "I experience". We investigate this in d.E. by looking for this "I". Is there a separate "I", or is there just an Experience that thought conceptually divides as such: "I" + "what is experienced"?
There is an assumption that there is a perceive-er that perceives. This is propagated by a belief, as expressed by a thought such as "I am the perceiver". We investigate this in d.E. by looking for this perceiver. We can see that there is no such thing as a perceiver, just a perception and thought dividing it in to an "I" + "body" + "perception through the senses".
A sound is heard, then there is a thought "I hear a sound". We can investigate and see that there is no hearer of sounds, just sound. If there is something felt and assumed to be the hearer, or self, is it anything more than some other sensations? or that sense of Aliveness? or another thought?
"I feel my body against the chair" a thought says. So, we investigate d.E. and see that there are sensations that are habitually labelled "body" and other sensations we refer to as "feeling of chair against body". When we investigate where this "I" is that claims these sensations, it cannot be found, as there is either another self-referencing thought, some sensations or another aspect of Experience.
We can pick up an object, and look at it. We might say "I am looking at the object". We then test this conclusion to see if it correlates with d.E., and what we find is that there is a sensation of seeing, and maybe some sensations that we usually label 'head' or 'eyes', or even other feeling-sensations labelled "body". A thought may arise with the conclusion that these are inherently separate, and that one is "self" and the other is "what is observed". When we test this out we see that there is never an "I" looking, never a watcher, never a seer. There is only seeing, only feeling, only Experiencing. We can say that it is simply Experience experiencing itself.
We look deeply in to Experience, and see that the assumptions of separation, self, "I", perceive-er or an experience-er are just references to Experience. There is never an actual separate object, just the perception of such, and thoughts labeling it. We deconstruct all these assumptions of there being a watcher, or a looker, or a hearer, and find that there is only Experience, never an actual separate self.
Is it possible there is just Experience, with no separate experience-er?