  Wave extraction plays a fundamental role in the binary black hole simulations
currently performed in numerical relativity. Having a well defined procedure
for wave extraction, which matches simplicity with efficiency, is critical
especially when comparing waveforms from different simulations. Recently,
progress has been made in defining a general technique which uses Weyl scalars
to extract the gravitational wave signal, through the introduction of the {\it
quasi-Kinnersley tetrad}. This procedure has been used successfully in current
numerical simulations; however, it involves complicated calculations. The work
in this paper simplifies the procedure by showing that the choice of the {\it
quasi-Kinnersley tetrad} is reduced to the choice of the time-like vector used
to create it. The space-like vectors needed to complete the tetrad are then
easily identified, and it is possible to write the expression for the Weyl
scalars in the right tetrad, as simple functions of the electric and magnetic
parts of the Weyl tensor.
