Use more lubrication next time around and make sure the surface is spotless. If the clay is dropped, it is useless as it picks up grit.
I personally prefer not using quick detailing spray as lubricant. I use the wash solution in a spray bottle or via the wash mitt while the car is still wet after the clean rinse during the wash. It also keeps the surface cool, which is beneficial for claying.
Check out detailing forums for proper detailing procedures. Detailingdomain, autopia, and autogeek forums are very valuable references. Once those swirls and scratches are corrected, the flawless surface can be maintained for many months. It is especially important for dark cars like our Black Mica's. Black reveal flaws much more than other colors.