If the Signal to Noise Ratio (SNR) is a figure of merit commonly used in many areas to gauge the quality of analogue measurements, its use in the context of Side-Channel Attacks (SCA) remains very difficult because the nature and characteristics of the signals are not a priori known. Consequently, the SNR is rarely used in this latter area to gauge the quality of measurements or of experimental protocols followed to acquire them. It is however used to quantify the amount of leakage in a set of traces regardless of the quality of the measures. This is a surprisingly lack despite the key role of measurements and experiments in this field. In this context, this paper introduces a fast and accurate method for estimating the SNR. Then, simple and accurate techniques are derived. They allow to process some daily tasks the evaluators have to perform in a pragmatic and efficient manner. Among them one can find the analysis of the electrical activity of Integrated Circuit (IC) or the identification of the frequencies carrying some information or leakages.