The Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument for the VLT is designed for discovering and studying new extra-solar giant planets orbiting nearby stars by direct imaging. In this paper, we describe the philosophy behind the SPHERE baseline data processing sequences dealing with calibration observations, and how these can affect the reduction of subsequent calibrations and scientific data. Additionally, we present the result of our detector simulations and the first tests of data reduction recipe prototypes.