Cried while writing a death scene. First one I've written that covers the dying and attempted life-saving. I've written grief scenes before, but now I'm actively killing a character. *sob* This death is a HUGE blow to my Female Main Character. Breaks her heart. I'm trying to be as real as possible with the stages of her grief.
Everyone grieves their own way, and since my FMC is a warrior, a hero, she does her best to save this life and when she can't, she avenges it. She's in shock and pissed off. She loves this person and it isn't fair. Death rarely is.
It's hard to talk around the specifics of the scene because of spoilers, so I can't say how she deals with it and what comes next, but I hope I'm saying enough to give you a little taste of what goes through a writer's head for these kinds of scenes.
Personally, I've experienced a lot of death, so grieving is very familiar. The most surprising thing, I think, to me is that grief differs even inside one individual. Circumstances matter. Relationship to the deceased matters. Was it sudden? Or a lingering illness. Was it a close relative? A friend? Someone you admired? A boyfriend/girlfriend or spouse? The age of the griever also matters. Children grieve differently than adults. Depending on age of the child, that denial phase can last a long time because death is still a very foreign concept. In the reverse, someone with a lot of life experience might find it almost easy to grieve because it is familiar. I could go on and on about specific circumstances, but you get the gist.
Ever watch a show that has frequent character deaths and became numb to them after a while? If you're a Joss Whedon fan, you know he kills at least one major character in everything he produces, and it's usually a death that ends a couple. If you're a Vampire Diaries TV show fan, you know deaths are so common they're rarely shocking anymore, and frequently it's not a permanent death. As a writer, if you're going to kill a character, always make it count. Make it count to the main characters. Make it matter to the plot. Make it resonate with the audience. I think as soon as your audience says "whatever" to another death, you're going off course and you've played this card too many times. So even if "no one is safe" is your writer's motto, take the time to build the characters enough that we care about each death.
My goal is to make you weep when the good die and cheer when villains bite the dust. If I've managed that, it's a good day.