The application of optimization criteria both in sample preparation and instrument configuration is very important in Mössbauer spectroscopy in order to compensate for the long periods of time required for the accumulation of spectra with an adequate statistical resolution. The criterion of optimum sample thickness is rather well known in the Mössbauer community. In this work we emphasize the criteria for optimum saturation level due to dead time and optimum window configuration in the gamma detection system. The analyses of these criteria are formulated under the constraint of maximum line statistical resolution with a given fixed time for spectrum accumulation. It is proposed that the simulation of the calibration spectra taking into account dead time saturation and background counts is useful to diagnose the presence of these effects in the spectra taken with standard absorbers. An example is described using aluminum foil as absorber.