We began a perpetual diary last year as a family, starting on the day we purchased our new house. It was symbolically important for us–a start to a new life, and one we wanted to remember.
It works this way: You fill a recipe card box with index cards. Add dividers for each month. Every day, you write the date (but not year) at the top of a new card. Then, you write the year on the first line. Next to it, write a bit about the day. I tend to focus on just one moment of the day. They can be short, like the example below (March 22–2020: Made strawberry pretzel dessert for the kids. Laughing a bit at old recipes.), or they can be longer. Different members of our family write (or dictate) it, which helps me see what different people think is important.
If we have friends over, we may ask them to make an entry for the day.

Above, a wooden box is filled with notecards, divided with dividers with the month written on them. The card for March 22 is lifted from its place in the year to show the words written on it.
By next August 16, we will have completed a full year–and will then add the 2021 entry below the 2020 entry. One goal is to preserve small memories of our daily life, but another is to help us see the big changes that can happen in a year.
This present moment is hard, and there is no guarantee that a year from now, things will be easier. But, even in that case, I think this perpetual diary will help us remember what we have gone through–and that amid the hard things, there have also been sweet moments worth remembering.