My youngest sister passed away June 19, 2009. She was 27, and it was sudden. I know the death of loved ones is never easy, but it seems like it is more of a punch to the gut if it is sudden and unexpected. The main thing that helped me after she passed away was knowing that SHE isn't dead. As a matter of fact, she is more alive than I am! For a long time, I talked to her (not praying, just talking to her). I know that we are separated for a time, but will be reunited. Eternity is longer than earthly life. Sometimes, I tell people that we did not lose her, because we know where she is. I can not imagine what it is like to mourn a person who is unsaved. That would be almost unbearable.
One of the things that helped me cope right after her death were hymns, and reading the stories behind hymns. Many were born out of grief. Another thing that helped my mother and me that first Christmas was Operation Christmas Child. We had zero desire to celebrate, but it was lots of fun buying things and packing shoe boxes.
I would say that one of the biggest things that gives me comfort is there were no hard feelings between us, the night before she died we were joking around. That means something to me, and I hate to hear about people who are estranged from family members, because I believe they will regret it if their family members die before things can be put right.