So, after giving thought and reading on death and/or the meaning of life (two completely different topics, but very related), I have found mindfulness practice the most useful method for coming to grips with it. Keep in mind I am a beginner ERE-er and mindfulness practitioner, but I hope this helps.
The weird thing is, reading this meditation once in a while (maybe every couple months?) has done nothing to change my tactical approach to life and early retirement explicitly (or planning-wise), but it has done a great deal for helping my interpretation of events, including deaths of other people or pets that I am close with and therefore I would be crazy to say that it has not had an impact on my well-being. Every time I read and meditate on these realities, my fear of death is lessened (although clearly I am not in an intentional pursuit of it!), it just is.
A. DEATH IS CERTAIN
1. There is no possible way to escape death. No-one ever has, not even Jesus, Buddha, etc. Of the current world population of over 5 billion people, almost none will be alive in 100 years time.
2. Life has a definite, inflexible limit and each moment brings us closer to the finality of this life. We are dying from the moment we are born.
3. Death comes in a moment and its time is unexpected. All that separates us from the next life is one breath.
B. THE TIME OF DEATH IS UNCERTAIN
4. The duration of our lifespan is uncertain. The young can die before the old, the healthy before the sick, etc.
5. There are many causes and circumstances that lead to death, but few that favour the sustenance of life.
Even things that sustain life can kill us, for example food, motor vehicles, property.
6. The weakness and fragility of one's physical body contribute to life's uncertainty.
The body can be easily destroyed by disease or accident, for example cancer, AIDS, vehicle accidents, other disasters.
C. THE ONLY THING THAT CAN HELP US AT THE TIME OF DEATH IS OUR MENTAL/SPIRITUAL DEVELOPMENT
7. Worldly possessions such as wealth, position, money can't help
8. Relatives and friends can neither prevent death nor go with us.
9. Even our own precious body is of no help to us. We have to leave it behind like a shell, an empty husk, an overcoat.
Full reading here (I removed the convictions):
http://www.buddhanet.net/deathtib.htm