Thank you everyone for your comments. It is indeed a big topic. To answer some of your questions.
Miranda. It is still of course worth sending love to those who have passed, especuially in the immediate period following death, as this can provide great comfort in the time before the actually do pass on. And it does indded help us to connect to them in some way. But it is important to let them let go any residual attachment that may make it harder for them to move on. So giving permission or expressing gratieude for what has been shared with an expression of letting go is important.
Sara. The Tibetan Book of the Dead, gives an outline of the areas of the psyche that we revisit throughout the dying process. The point at which we pass on will be determined by how strong our attachemnt is to the various areas of clinging that remian ( notwe this can be either attachment rooted or aversion rooted, as well as kindness or generosity, appreciative joy or merit. So the karma that leads us on is ethically variable and depend upon where our strongest charge lies and regarding what. Hence the three roots of the mind ie greed / non greeed, aversion / non aversion, ignorance/ non ignorance, and how they are expressed within the rebirth linking consciousness determines the underying quality of our mind and conditions in which we find oursevles. Our practice is designed to help us recognise the minds true nature as the clear light of awareness, and not to cling on egoic fixations during the dying process.
Alistair. The time spent to pass on is actually it feels, quite indeterminate. From experince I feel it is usually between a few days and a few weeks, but occasionally if the attachment to what we are leaving behind is very strong we can reamin in this intermediate state for a long time.
Denise, it feels as if your Dog, may on account to attachemnt to you still remain in that state, if you genuinely are feeling his presence still. To know for usre you need to try to discern clearly whether this is a direct perception or arising as an association with him and the places you still feel his presence. Regardless of this, sharing merits may help him to pass on if he is still around you.