This may seem to be a paradox; but it seems possible to pursue Primary Thinking/ Final Participation in a deliberate and purposeful fashion - and without falling into the trap of trying (and inevitably failing) to coerce the higher consciousness to a lower agenda.
Primary Thinking must come from the real self - so we need to attend to the real self and strengthen its influence. The real self has its own agenda; and that agenda is intrinsically aligned with Creation - because to think with the real self is to participate in divine creation.
The direction, or subject matter, of primary thinking cannot be imposed; but needs to be recognised - having recognised it, we need to harness our will to that matter. This may be resisted by our lower, contingent selves - since the creation agenda does not pursue this-worldly-expedience or advantage; and may not make much sense to us.
But if we can recognise a spontaneous, inner impulse from the Real Self, then by following that, we may experience more Primary Thinking: more explicit, more frequent, more intense...
This has (apparently, so far as I can judge) happened to me over recent months through my reading of the Fourth Gospel (aka. the Gospel of John). I felt a sustained, inner-derived urge to understand this gospel, above all other scriptures; to understand Jesus in light of this gospel; and I have followed this urge.
And I have reported some of the outcomes in this blog; although the primary outcome was actual direct and wordless experience - the blogging is merely a selective summary, expressed in language.
And this activity has been associated with a considerable increase in Primary Thinking, with a considerable increase in intuitive knowledge. I am now better able to recognise Primary Thinking when it happens, and am able to practise attending to it, taking it seriously, and according it authority.
I now, retrospectively, perceive that this wish to read and re-read the Fourth Gospel, to brood over it, was an impulse coming from my Real Self.
This may be a general lesson. If or when we do feel such an impulse - we should evaluate whether it is from the Real Self; is, perhaps, the Real Self trying to break out from the mass of distractions, false personalities, and evil impulses that make up the everyday mind.
This is something that could only be discovered, not imposed; and perhaps that is a quest that many people could benefit-from? The quest - that is - to discover the subject matter, activity, situation, person or whatever it may be - that their Real Self most deeply and sustainedly wishes to be the medium for its own growth and strengthening.
And having discovered it; do it: pursue this as the medium for theosis, by means of an explicit recognition and prioritising of Primary Thinking.