To become a scribe requires rigorous study and training-and great skill. Certainly, a person who has not carefully studied the laws pertaining to composing a Torah scroll cannot be a scribe. Above all, however, the scribe must be a G-d-fearing and pious person, dedicated to the sanctity of the Torah scroll.
The scribe may not rely on his memory, but must copy the letters, word by word, from a kosher Torah scroll or a copy of a certified Kosher scroll. A right-handed scribe writes only with his right hand; a left-handed scribe, only with his left hand.
The Torah scroll, and especially the Names of G-d contained therein, must be written with utmost purity and devotion. It is therefore customary that the scribe immerse himself in a Mikvah (ritual pool) before beginning his work. He also recites a blessing at the outset of his work and before each time he writes the Name of G-d.