Yes, get your will in order. Get your wishes known for what you would like happen if you are unable to make the decision yourself. This is so that your relatives don't have the Dukkha of having to make that decision for you - this is compassionate.
Steve's mother died recently. She had made a living will and later she had a stroke. Her swallowing mechanism was paralyzed so she could no longer take food and she also was unconscious. She had made a living will that stated that she didn't want to be kept alive by artificial means, so because she had made a living will, her family didn't have to decide for her at that time. And so the family didn't have to get into arguments about it. Get your financial stuff in order, yes, this is through compassion.
I also know of a person who inherited something from a relative but someone else apparently had been given some handwritten thing so there was a big legal battle over it. Having your financial stuff in order is very helpful for the people that you want to leave your stuff to.
As to a memorial and funeral - yes, it would be very helpful to let others know, because if you are still hanging around, it would be nice to have a memorial that you like rather than thinking, "Oh, that is a lot of rubbish!" or, "Why didn't they do this for me?" Who is to know? I have made it known to my assistants what I would like to have happen at that time. They know that I want a lot of chanting and if I am unconscious I have some special chants I would like done; and talk about my good stuff and don't start grieving about me, please, if I am still around.
So yes, it is helpful to know what people would like. As far as appropriate preparation in our own mind, so that after we die we are not hanging around, maybe by writing all of this down we won't feel we need to hang around, we got it all in order and we don't have to hang around.
I think Steve talked about the toilet, right? If you get it all in order, you won't feel, "Oh, I have all that stuff to do!" and keep hanging around and so on, wondering where the will is, etc. Then we will have everything in order.
As far as getting our own mind ready for it, learning how to reflect on our good past Kamma is very helpful. Learning how to reflect on your inner refuge is also very helpful. But in order for these to come up at the time you feel like you are dying, you have to practice them and believe in them. Steve has, I think, a favorite Compassion/Lovingkindness meditation. I have a favorite reflection on the Buddha. We practice it often, we practice getting ready to die when we takeoff in an airplane, and when we land, getting the mind together by focusing on a meditation object.
You can practice it any time that you have fear, maybe do it as a dry run. It is very helpful. I remember one time I had a sickness, I had a lot of pain and it increased in intensity. I thought I better go to the bathroom, then the pain increased, and it increased, and it was getting very strong, and I thought I better call Steve; but then I thought I might not have the time, I might be dying, then fear arose and I thought, "Fear. I don't have time for that! What do I want to think?" And I observed that moment of awareness, seeing the fear and my reaction, "I have no time for that! I might be dying." But if I hadn't had reflected on death previously I might not have had the thought, "I might be dying."
And then I put my mind to my meditation subject. I also had to get down on the floor, because if I didn't get down on the floor, since it was concrete bathroom, then I might have died at that moment from the fall. So this was very fast in the mind and as I was about to pass out I put my mind on a meditation object, and I then passed out. Fortunately I only scraped my head a little, then when I woke up - because of course I didn't die - I was very happy because my last thought that I had was my meditation object.
So preparing ourselves to die while we have any sickness is helpful; learning how to see fear, note the fear with some objective awareness, and have a bit of a death reflection may help our practice to prepare for the time that we die.