My bonding with the kids normally involves movies and popcorn. Other times we would spend hours in my craft room just tinkering on interesting projects that boost their creativity. Pom Pom Bookmarks Make cute little pom pom bookmarks with yarn.
You don't need this space to truly feel cluttered, so little furnishings is critical. If you're remodeling an attic space, look at creating an open staircase from the ground below and leaving the area which connects with the remainder of the home open.