You do not need to document every minute of Christmas to preserve the parts your family will want to remember.
Take one repeatable photo
Choose a picture you can recreate each year: everyone around the table, the finished cake, pajamas by the tree, or the first ornament hung.
Write one sentence
Record who was there, what made everyone laugh, or who found Tomte. One sentence is more likely to be repeated annually than a full journal entry.
Use one shared album
Create a phone album for the tradition so photos from different years stay together and are easy to revisit.
Include the finished creation
If The Tomte Cake is part of your season, photograph both cake houses before they are eaten. The decorating styles often become a surprisingly good record of children's ages and personalities.