Cynthia Tingey trained at the Regent Street Polytechnic where she won a medal for theatre design. She began working in the theatre in 1952. Her career included a five-year period as house designer for the theatrical costumiers, Bermans, as well as work on West End productions, department store exhibitions, and designs for over fifty films, but it was as a costume designer for pantomime, variety and cabaret that she became best known. She designed 15 of the London Palladium's annual Christmas pantomimes, providing costumes for well-known artistes such as Arthur Askey, Cilla Black, Cliff Richard and Tommy Steele. Throughout the 1950s, '60s and '70s she was responsible for the costumes for cabarets at many of the major London nightclubs and hotels, and she also designed summer variety shows, ranging from the London Palladium's extravaganzas to seaside specials at Blackpool and Great Yarmouth. She designed many of the shows for the Central London nightclub founded by and named after Danny La Rue, the popular entertainer and 'drag' artist. The club opened in 1964 and until its closure in 1972 was a fashionable venue with a clientele that included film stars and royalty. Princess Margaret and Lord Snowdon, Noël Coward, Judy Garland and Elizabeth Taylor were all patrons.

Cynthia Tingey often made her designs on black or coloured paper to highlight the colours required for the costumes and would include a number of designs on the same sheet of paper to show how the costumes would work together on stage. Her designs for showgirls might all use the same colour but be of different shapes and cuts to produce a varied stage picture.