After Sam makes up with Darrin, Sam snaps her fingers and her two bags of luggage, sitting by the front door, lift off the ground (the small bag on the left side of the camera shot & the large bag on the right). However, the very next camera shot has the bags magically going up the stairs in the opposite positions.
When Endora makes the Stephens' phone ring, to delay Darrin coming down before Samantha can finish his breakfast, the 2 subsequent rings occur too fast to have been rotary dialed (even if the number was of seven 2s) & connected. Darrin should have realized it was his mother-in-law's doing at the 2nd occurrence, not after the 3rd time.
When Darrin heads up the stairs, during the argument with Samantha, the fake banister wobbles when he touches it, making it obvious that the scene was shot on a studio set rather than in an actual house.