When we make our work and our process explicit, and we do retrospectives, it makes sense to have a retrospective column in our Personal Kanban. The thought here is fairly simple: at the beginning of each day move tasks from Complete into Retrospective. Then, at the end of the week (or whenever you wish) take a look at the tasks in the Retrospective column. They will remind you what you did over the retrospective period.

This is also handy if you need to do your timesheets every week and want to actually remember what you accomplished.