I do this easy little thing in my room that 1) Reminds kids of what we've done, 2) shows admin a public record of our learning, and 3) makes for easy room decorations!
What is it? A timeline of subjects we have studied.
You could choose to do the main idea for the month or art project of the month. September was government, October was graphing, November was rocks and minerals. As you can see, it is super simple and easy. Really doesn't take much effort and my kids love reflecting back on it!