The common or general instructions seem intended to be the base or background upon which all the uncommon or detailed instructions build. For me personally, it seems that I rarely need anything beyond the common .... whose teachings are:
Do not seek to prolong the past.
Do not seek to grasp the future.
Rest evenly in cognitive lucidity, free from conceptualisation.
That seems to be all I need. Any time I recollect this, in or out of formal practice, it brings the view and method into focus, and provides the means into which to relax, and let go.
'Do not seek to prolong the past' ..... don't get caught up in thoughts of the past. Once it's gone, let it go.
'Do not seek to grasp the future' ... similarly, don't get caught up in thinking about the future. It may or may not come to pass. If it does, fine, then deal with it when it does. If it doesn't, then also fine.
In both cases, thinking of the past or the future, these thoughts can be let go of - not pushed away or rejected, or even judged or analysed, but just let go of, naturally to return to from whence they came.
'Rest evenly in cognitive lucidity ....' .... resting ... relaxing the mind, with appropriate effort, neither too slack and loose, nor too tight and taut ... resting, relaxing in awareness, cognitive lucidity, the awareness which knows directly that which appears to arise ..... The natural state is one of relaxation, and meditation is the allowing of that state to unfold and enfold.
'..... free from conceptualisation' .... resting evenly in awareness of the present moment, without thinking of the present moment, of what appears to arise, of what you are doing, meditating, or not, without any conceptual elaboration .... without unnecessary thought ...
just resting the mind in its own nature .. letting go into awareness ... awareness of the present moment, without conceptual elaboration .....
This is just what I need, at any moment ..... the long and the short of meditation .... the common Mahamudra instructions entirely suffice .....
the pith instructions of the Realised Ones .....
How can we ever repay their kindness and blessings ...... ?