Memory planning is a term used in the community to describe a cross between planning and scrapbooking. It is typically more artistic and involves looking back on events rather than planning ahead, and incorporates a bit of journaling. Personally, I like having one as a decorative planner to document memories, since I have a separate functional planner for tasks.
If you have a planner you'd like to use but don't necessarily need, this might be a setup to consider. You can use your craft supplies, photos, doodles, and anything else you can think of to embellish your days. Even the smallest details, such as your outfit or a song you heard, can be interesting to look back on. When I'm filling out a planner spread for days that have already happened, I like to think about what future me would be curious about.