Ask HN: How does your group celebrate success?

My group at work recently brought up the point that we don't celebrate success. We get so caught up in schedules, putting out fires and working to meet the next milestone that we don't stop to celebrate any of our successes. We could blame senior management for not setting the right atmosphere but we also determined that "we" should be able to celebrate success on our own. How DO YOU celebrate success within your own groups? Any feedback, recommendations or other ideas are welcomed. Thanks in advance.