During the past decade, time-resolved microwave conductivity (TRMC) has evolved to an established, powerful technique to study photoactive layers. With this feature paper, we aim to fulfill two goals: (1) give a full description of the photoinduced TRMC technique, including experimental details and data analysis, and discuss to what extent the TRMC technique differs from more conventional DC techniques and (2) illustrate the potential of this technique for probing charge carrier dynamics in photoactive materials. For these reasons recent studies on conjugated polymer:fullerene blends will be presented and discussed. The findings from these studies have advanced the insight into the mechanism of charge carrier generation and decay in polymer:fullerene blends, which allows us to improve the efficiency of organic photovoltaic cells based on this active layer architecture. In short, it is shown how the TRMC technique can be used as a versatile method to screen the potential of new photovoltaic materials.