Continuity mistake: When Carrie is showering after being stood up at her party she is not wearing mascara as she stands with her face under the water, then as she opens the curtain to talk to Charlotte again there is no mascara. She puts her hands briefly over her eyes and when she takes them away, mascara is visible all over her eyes and cheeks.
Revealing mistake: When Charlotte arrives at Carrie's apartment to pick her up, Carrie is in the shower. As Charlotte walks towards the bathroom, there is a clear shot of Carrie showering. Sarah Jessica Parker appears to be wearing some sort of minimal tan colored undergarments, to protect her modesty while filming.