The final shot of Prue closing the manor door in the first season credits is actually from the unaired pilot.
Season 2; Episode 2 "Morality Bites" is the only episode that showed only the sisters and nobody else in the opening credits.
People who don't appear in the episode do not appear in the credits, so there are several versions of credits for each season accommodating each person's absence.
The opening credits for the first 2 episodes of the series didn't show the girls using their powers. As of the third episode, a new set of credits were made showing each of them using their powers.
In the 2 parts of the fourth and fifth season premieres, the opening credits were not shown. It just featured a glowing triquatra.
As of the fourth season, the style of the opening credits completely change, focusing more on supernatural objects and shots rather than clips from other episodes.
The end credits play over a shot of the Book of Shadows on the stand in the attic from season 2 onwards.
4 different pieces of score music were featured during the end credits of the first season, changing each episode. Since the second season, only three of the four pieces were used.