I never have come across killing a character of mine yet, or having them be killed. o wo So I haven't had that issue yet..
HOWEVER.
I HAVE had a character come terminally close to death, like a coma, or poison, etc. And once, a character of mine even became handicapped, or had a limb amputated. So.. that does change things up QUITE a bit..
I think, with killing characters off.. If I am the GM, and have to do it to someone else, I grab their permission first, and if they want them to be killed off, I would try to do so in a tasteful manner that makes sense, and could possibly give some fuel to the other players to continue on the story.
If it is I who wants my character killed, or is asked by a GM to have something dangerous happen to my character, I would work on making the final paragraphs of posts as epic as possible, and make sure they are 'off'd in the right way for the particular roleplay.
I don't really like when characters die that are being actively played, though.. It's kind of a tough subject, and kind of sad to me..
But it can make sense if someone plays a character that turns out to not be quite the right fit for a roleplay. Especially tabletop, with stats and all..
Like.. a sort of do-over chance to get back into the Game in the right way.. you know?
I don't know if this made sense. 8D I tried.