The power spectrum of galaxies provides invaluable information about dark energy, gravity and initial conditions of the Universe. It is therefore extremely important that we measure it in the most optimal way possible, especially given that the total cosmological volume available to galaxy surveys is limited. My talk will be based on a recent work by my group that looks into the ways of measuring

the power-spectrum when multiple galaxy types are present in the overlapping volume. We developed a weighting scheme that can reduce the variance of key measured cosmological parameters, such as e.g. the growth rate, by up to 40 per cent for future surveys (eBOSS/DESI).