Every year, I think I am going to send out Christmas cards (I haven't in years). During the holiday season I get all the cards and think "I should send them out as well, too late, but I will get an early start next year". Then the next year, the same thing happens. Why? I don't plan, I only think.
The same principle applies to year-end planning. As you do it, you will find some things that are difficult or not as efficient as it could be. You may even think about how it can be done better. The statement is something like "I should have organized these files better so I could find things faster".
This is where your personal organization system comes to the rescue. When you think of something you could do to simplify or streamline the process, make a note of it. During your weekly review, combine all the notes related to it. Then put on your task list/calendar the task to review all the notes and come up with a plan for next year. You don't have to do it right away, but you certainly don't want to wait until July of next year to do it. Then complete the tasks, set up the new process, etc. This moves from "thinking" about ways to improve to actually "implementing" improvements.
Bonus Content: apply this principle to anything that is done occasionally (like yearly). I've been involved with many projects at home, church, etc., where we debrief what we could do better next year and put it in the file for us to look at next year. Once next year rolls around, we forget all about the file and we do things the exact same way. Nothing is more infuriating than that. And volunteers who have to face the same frustration year after year will stop helping.