Techniques include the passing of the seasons, when he's doing that "angry dance" (u know when he dances like mad up the street when his teacher and family are fighting) the techniques are:-
Hes in the small toilet room thing and he starts to dance and cant control it, then he bursts out into the yard (this represents his move Into the world), when he finishes dancing he hits an iron fence - represents barrier.
The scene when he first begins ballet - hes on one side of the Barre and the girls are on the other is another barrier, shot of his boxing shoes in amongst the girls ballet slippers, the scenes where he was practicing dancing in the bathroom (the spin thing) represents his small world or being boxed in, but also his determination as time passes to get it right.
Conflict between him and his father are shown particularly in the scene where Billy throws his whole mattress off his bed to hide the ballet slippers and his father comes in. The angle of the shots show Jackie as a powerful figure, his suspicisions of Billy and his sentimentality of the boxing gloves.
The scene when Jackie catches Billy dancing with the girls the iron gate thing represents a barrier between Billy and Jackie