Make homemade bubble solution with liquid dish soap and water. Start with a cup of water and a tablespoon or two of dish soap (Dawn seems to be the most popular choice for making bubble solution) and mix. You can add a little corn syrup or dissolve some sugar in the water to make the bubbles last longer. You can use wands you already have or children can create their own with pipe cleaners or flexible wire.
Goal: Children will experiment with creating bubbles that are different sizes and observe changes from the bubble solution to bubbles to bubbles as they pop.