As for guidelines for introducing these experiences, the basics still apply. Limit the number of materials (points and lines) initially until the child is ready to experience more complicated arrangements. Perhaps you might introduce this new Gift by returning to the solid cube of Gift 2. Allow the child to recognize the point and the line and naturally construct two-dimensional forms (triangle, square, etc.). The child will naturally tie the ideas of all the previous Gift play together as he/she becomes ready for this concept.