What I have done in the past to memorialize and commemorate the death of a loved one; for my mother, my father and my two favorite uncles, was to plant something for them, somewhere. Somewhere where you can plant something and it won’t be disturbed, at least not for a good long time. Something that reminds me of them, and for me it has always been a bulb or perennial of some sort, something that comes back every year. Something that lives on. That is what I like to do, among other things, but it is personal. I prefer that to merely commemorating important dates like the anniversary of the death, or birthdays or holidays, though I do that to, but my focus on that kind of thing diminishes over the years. But the day lilies and the roses and the tulips and the daffodils and the azaleas keep blooming, year after year, even if I have forgotten to remember or note a particular or meaningful date. And they are a reminder of life, not just a reminder of death. But, as someone already said, it is a personal thing. That’s just what I do.