I don't know what you mean by the 4 and 2 method.
However,
Our method is the Referee signals (bent arm with a fist) indicating he has 11 players, the two wings would then have a flag only if their are more than 4 in the backfield.
Or, if the Referee signals (10 fingers at waist level) indicating he has 10 players, the two wings would then have a flag only if their are more than 3 in the backfield.