1. Read/discuss/debate passages from your Holy Book of Guidance that illustrate collective work and responsibility. Here are two of my favs': Ecclesiastes 4:9-12 - Two [are] better than one; because they have a good reward for their labor. Proverbs 27:17 - Iron sharpen'eth iron; so a man sharpen'eth the countenance of his friend.
2. Clean your house/office/ personal area together.
3. Have that difficult discussion lovingly to heal that emotional-wound.
4. Coordinate and develop a list of chores for the members of your household, organization, fellowship, office.
5. Meet with that person that you and yours have harmed and take responsibility for your collective impact upon that person/entity.
6. Become involved in an activity to improve the appearance of your neighborhood.
7. Donate to a cause collectively with your group of influence.