Dear Aliciapc,
You ask: �In English, how do you say "Cada maestrillo con su librillo"?
A literal translation is something like: �Every Teacher has his/her own Method�.
There are idiomatic expressions.
�Every Man to his own Trade!�
�To each his own�
�Cobbler, stick to your Last!�
�Horses for Courses�.
�Have the Courage of your Convictions!�
�There is more than one way to Skin a Cat�.
�To go one�s own Way�.
�There�s Method in his Madness�.
�To go by the Book�.
�To have the Last Word�.
There are probably others which are appropriate.
Les