Acta virum probant.
The doing proves the man.

Acti labores jucundi.
Work done is a delight.

Ars usu juvanda.
Art is to be helped by practice.

Virtutem posuere dii sudore parandam.
The gods have contrived that excellence is to be had through sweat.

Providite mihi aliquiem bene psalentem.
Give me someone who plays well..