you can first learn concentration skills during out-of-studio training,for exsample when you are doing yoga,pilates,callanetics...you can put on your training face.
The training face involves being totally focused on the excercise which you are engaging.
This means no talking or looking around,concentrating fully on optimal execution of the excercise.
Beginning the development of concentration away from the studio,allows you as a dancer to identify performance and irrelevant cues in a setting with relatively feew distractions and also enables you to practise good concentration in a stress free environment.