Continuity mistake: In the scene where Carrie and Miranda are eating cakes outside the shop, talking about Miranda having to be supportive to Steve about his basketball competition, keep an eye on Miranda's cake. She takes bites out of the cake and then when it is down to the last bite, the camera shows Carrie, then shows Miranda again with the cake suddenly full.
Continuity mistake: At the furniture show, when Carrie is introducing Big and Natasha to Aiden, Carrie accidentally spills her coffee on Big. A coffee spot that splashed on Carrie's upper blouse keeps appearing and disappearing throughout the scene.
Attack of the five foot ten woman - S3-E3
Continuity mistake: The episode 'Attack of the 5 foot 10 woman' in season three, when Charlotte is afraid of the sauna. She is running into the sauna with a towel wrapped around her waist. The towel comes loose and is nearly falling off - but in the next shot it is neatly tied around her waist.
The big time - S3-E8
Continuity mistake: In the scene where Miranda is woken up by the dog barking and finds that Steve hasn't come back to the apartment that night, the puppy she picks up is older than the puppy Steve picks up when he comes back to the apartment the next morning.
Attack of the five foot ten woman - S3-E3
Continuity mistake: When Magda opens Miranda's 'goody drawer' Miranda quickly slams it shut it with her hip. In the next shot, it is still open a little way.
Continuity mistake: When Samantha and her date are in the health food restaurant, she orders wheatgrass shots. The waiter pours them, filling the cups to the brim and then sets one on the table in front of each of them and we see again in a close up that they are both full up. Yet when Samantha picks up hers to drink, the liquid level has gone down a little way.
Continuity mistake: Carrie is trying to drive a car up a hill and a grey car drives close to them very slowly. When the car is side by side to Carrie, the shot changes to a wide angle and the grey car has vanished.
Continuity mistake: When Carrie and Shaun are laying on the floor of her bedroom, she has her left hand resting on her chest. But in the very next shot; her left arm is laying across her stomach, and her left hand is curved around her right waist. No time has passed in between these shots. (00:12:25)
Continuity mistake: When Carrie gets to the WB Studios and stops at the guard's place, the image alternates between close and wide shots. The cars and people surrounding Carrie are totally different depending on the shot.
Continuity mistake: The people walking behind Trey and Charlotte close to Tiffany's is totally different in the side angle, than in the front shot - check out the African-American woman, for example.
Running with scissors - S3-E11
Continuity mistake: When Carrie is in Big's kitchen, and hears Natasha come home, she tries to leave in a hurry. She puts on her blue levi jacket, so it's about halfway on with her left arm in the sleeve. But in the next shot of her, Carrie is suddenly wearing only her pink bra and carrying the blue jacket. As she unlocks the door and starts running down the stairs, she throws on the blue levi jacket for the second time. (00:25:15)
The big time - S3-E8
Continuity mistake: When the girls are in the bathroom talking about their periods and doing their make up, we see Carrie remove the hair scrunchie from her wrist with her teeth twice, once in the mirror in a shot from behind, and then again from the front.
Continuity mistake: During this scene when Samantha is confronting her new assistant, the office set-up is completely different than before, when Nina G. was working for her. The assistant office space is much larger, glass desk, different angle, next to small conference room instead of Samantha's office, etc.; obviously not the same office set as previously used. Yet Samantha has not changed offices at all during this time period, as it wasn't too long ago when she fired Nina G. Something as major as changing offices would definitely have been mentioned in the plot (as changing apartments always is); and there hasn't been enough time since she fired Nina G. (00:13:45)
Suggested correction: You're assuming that moving to a new office must be a plot for a new episode, which makes no sense (plus, it's a show that revolves around sex, women, restaurants and bars). Furthermore, the episode you mention is S2E17. Many months have passed and it's perfectly plausible for Sam to move some place else.
Continuity mistake: When Carrie is lying on her bed, she is wearing yellow pants over a green top. The top portion of her pants is unbuttoned/unzipped as she moves. But after she picks up the phone to call Big, she is sitting up on her bed, and her pants are suddenly buttoned/zipped completely up. There was no opportunity in this sequence for her to have closed her pants. (00:12:15)
Continuity mistake: When Steve arrives at Miranda's place he cuddles the puppy, but his left hand's position is not continuous between shots when he thanks her for sleeping on the couch.
Continuity mistake: When Carrie debates with Miranda whether to call Big or not, Carrie holds the pillow close to her chest in one shot, but over her thighs in the other.
Continuity mistake: When Carrie says Aidan is a good man she places her hands on his face, but his collar gets stuck in between. From a different angle the collar is several inches below.
Continuity mistake: During the party, when the music starts the man with white bermudas and light blue shirt behind Charlotte keeps changing positions between shots.
Continuity mistake: In the duck pond, Big's wet hairstyle changes between shots. Also Carrie's, from soaking wet and straight to slightly curled.
Continuity mistake: After Trey and Charlotte have sex, the way his jacket lies on the box changes between shots.