Bewitched - Season 7 - Eps 12: Samantha's Magic Potion
Darrin isn't doing very well creatively and decides to take a vacation. When he returns, he comes up with a sure-fire sales pitch for a very strict client, who rejects him on the spot. Darrin blames his creativity block on Endora and wants Samantha to give him some magic creativity. Samantha gives him a potion that insures great confidence and presents the client with the same rejected idea, which passes. Samantha tells him that his confidence was his own and that the potion was nothing more that soda pop.
About Bewitched

Title: Bewitched
First Air Date: 1964-09-17
Last Air Date: 1972-03-25
Status: Ended
Rating: 7.861/10 (from 695 votes)
Language: EN
Seasons: 8
Total Episodes: 254
Network: ABC
Genres: Sci-Fi & Fantasy, Comedy, Family, Drama
Production Companies: Columbia Pictures Television, Screen Gems
Synopsis
Samantha Stephens is a seemingly normal suburban housewife who also happens to be a genuine witch, with all the requisite magical powers. Her husband Darrin insists that Samantha keep her witchcraft under wraps, but situations invariably require her to indulge her powers while keeping her bothersome mother Endora at bay.
Cast

Elizabeth Montgomery
Samantha Stephens

Dick Sargent
Darrin Stephens

Agnes Moorehead
Endora

David White
Larry Tate