Yarn balloon spheres: Cut strands of yarn, blow up balloon. Mix equal parts craft glue & water. Dip yarn in glue, wrap around balloon. Hang balloon with clothesline & clothespin. Once dry pop balloon and remove. Modge-podge could work too.
DIY: Bubble recipe and refill station. Love the idea of reusing plastic cups from restaurants as the containers. Keep the bubble solution confined to one big refill container, and no worries about leaky, yucky containers hiding all over the house!