I find the ability to maintain equanimity, which can be developed by practice,
to be key in dealing with mortality. If you can get fear in general under control,
you can get fear of mortality under control. And managing fear is not just for
dealing with mortality, but rather for anything that requires a cool head.
How to practice maintaining equanimity? That is personal, and although I
can describe my practices of choice I wouldn't presume to say that they
would be the best practices for someone else. Some people meditate as
practice in staying centered, but for me no practice has been more effective
than rock climbing.
"Fear is the main source of superstition, and one of the main sources
of cruelty. To conquer fear is the beginning of wisdom, in the pursuit of
truth as in the endeavor after a worthy manner of life." - Bertrand Russell
And about mortality in particular: my experience is that appreciating
mortality is an ongoing process. I got my real introduction to mortality
by testing HIV positive in 1987. I didn't know how well I'd be doing in
1990, let alone 2012. I saw right away that I had never seriously
contemplated mortality before (normal for a young person). But even
after an experience of taking mortality seriously, there remains an
ongoing process of understanding it more deeply. I am not painting
a picture of grimness; on the contrary--mortality is very much a part
of life, and appreciating mortality is part of a well-rounded appreciation
of life as a whole.