Probably the biggest offender is the lack of clarity around the specifics of the project. Vague objectives lead to confusion. Reducing or confirming the scope of the project, and getting detailed on what you want to experience once the project is completed, can make a big difference. Put it in writing for reference.
Lead crystal glass has a higher refractive index than ordinary glass. Light kinks when it goes from the air into glass and again when it passes out of the glass into air. The higher the refractive index, the more the light kinks. White light is made up of red, blue, green and yellow light. These all have different properties so are kinked by different amounts. It is THIS that gives cut lead crystal its distinctive bright appearance.