With time I accumulated a bunch of rituals around beginning and ending of my sketchbooks. For exmaple - I always put a number and the date I started it in the beginning - immediately after I crack it open. Then I add my name and contact information on the inside cover too. I usually record what are my favorite tools on the first spread. This is always helpful when I want to remember "what was that color that I liked"
And I also like to weigh my sketchbooks - at the beginning and at the end - to see how much stuff I added (how I add stuff is described in this series of posts: Part 1 is about the reasons for adding all the layers to my sketchbooks and Part 2 is about the evolution of it. Part 3 is about materials that I use and has more examples. ). And this post will show you some weight gained on the covers: https://blog.apple-pine.com/2022/05/sketchbook-covers-end-of-sketchboook-141.html
It's a fun way to measure how much happened in this period of time, an attempt to take an objective measurement of something that is quite subjective.
Here is a short video about beginning of the Sketchbook number 144. I will make another one - when the sketchbook is finished to let you know how much it "grew".