Modulators of G protein-coupled receptors (GPCRs) form a key area for the pharmaceutical industry, representing approximately 27% of all Food and Drug Administration (FDA)-approved drugs. Consequently, there are a wide variety of in vitro plate-based screening technologies that enable the measurement of compound affinity, potency, and efficacy for almost every type of GPCR. However, to maximize success it is prudent to ensure that (i) the most suitable assay formats are identified, (ii) they are configured optimally to detect the desired compound activity, and (iii) that they form a basis for predicting clinical effects. To achieve this, an understanding of the pathways and mechanisms of receptor activation relevant to the disease mechanism, as well as the benefits and/or limitations of the specific techniques, is key.