Crean, who had a background in competitive fencing, began choreographing fights in 1932 when he was working in England as an actor in The Legends of Don Juan.

He received public acclaim for choreographing the impressive fight scenes for John Guilgud's 1944-45 season of Hamlet at the Haymarket, with a personal feature on Pathé News and in Post Magazine.

Crean and his partner Rex Rickman were frequently hired to stage fight scenes for theatrical productions as well as in films such as The Master of Ballantrae (1953) and Sword of Sherwood Forest (1960).

Crean travelled to the Canadian Stratford Theatre Festival in 1962 to serve as the fight arranger for Macbeth, directed by Peter Coe.

Among festival productions for which he arranged the swordplay, The Three Musketeers, directed by John Hirsch in 1968, received great acclaim for its stage action.