At the end of each week, I have students go through their corrected work and find a piece that they are especially proud of. It might be a page, packet, or just one problem they worked hard on. They take that work and reflect on why it is their 'WOW' piece and hang it up. Before starting this, we brainstormed as a class what WOW work and not WOW work looked like. The kids seem to really enjoy doing this and I've noticed an improvement in the quality of their work overall. The template I use for the reflection is available (for free) at my store!