Manners made his directorial debut in 1978 at age 27, directing an episode of Charlie's Angels. Prior to this, he had worked as unit production manager on the show and as an assistant director on a handful of other projects. Other notable directorial credits to Manners' name include episodes of 21 Jump Street, Mission: Impossible, Star Trek: The Next Generation, Baywatch, K-9000, and The Commish.
Manners left his directing job at Stephen J. Cannell Productions in 1993 to work on the television series The Adventures of Brisco County, Jr. He directed 7 of the series' 27 episodes, more than any other director for the show. He joked that he was the series' "mascot director". He was happy with the work for the series, and felt that it "stretched" him creatively. He said, "It really woke me up as a director, almost spiritually…" and that directing for Brisco was a large contributing factor to his later success as a regular director on The X-Files.
Manners signed on to produce and direct The X-Files in the show's second season at the advice of Rob Bowman, who had worked on the show in its first season, and James Wong and Glen Morgan, who were writers for the show and had previously worked with Manners on 21 Jump Street.
Manners, along with his fellow producers on The X-Files, was nominated for four Emmy Awards for Outstanding Drama Series in 1995, 1996, 1997 and 1998. Manners was referenced in the X-Files episode "Jose Chung's From Outer Space" with a foul-mouthed police detective named after him. Following the finale of The X-Files in 2002, Manners directed a number of small projects before signing on to direct and produce Supernatural in 2005.
