Whenever I'm finishing a topic and starting a new one, I usually make this activity with the kids.
I draw several balloons on the blackboard and ask them to try to fill each memory balloon with one word from the last topic we've learned.
For example, yesterday I wrote Food on the board and started drawing the balloons. It didn't take to long before the kids filled all the balloons.
After we do this together on the board, the kids copy it to their Portfolios. With this activity they recall vocabulary and they keep an organized bank of words on their Portfolios.