Sometimes, RPG.net provides some nice little concepts:
> On a somewhat similar vein, I can easily imagine myself dying, but I can't imagine
> myself being dead. I can't conceive of what it would be like to not be conceiving
> of what it would be like.
This might not work for everyone...but I recently found a neat way to get my head around this myself.
What you see when you are dead will be exactly like what you see behind your head.
By extension, your total experience will be exactly like the experience you are having right now, on another continent. Right now, I am nonexistent in Paris. I am experiencing an infinite array of "dead" states, briefly interrupted in space and time by this single life state.
Just like I can conceive of what I see behind my head (not blackness, not a void, but zero input), I can extend that to all my senses.
Of course, for me the next natural question is "Am I suffering, in Paris, right now?". The answer to this is clearly no, so I will not suffer in death. The rest of philosophical Epicureanism soon follows, for me at any rate. :)