Thermophysical properties often fall into simple, regular, and intuitive patterns within and among families, and these patterns can be used to fill in gaps in experimental measurements, to identify outliers that are likely in error, and to educate scientists and engineers to understand and anticipate expected behaviors. This notion is not new but has not been sufficiently exploited in the applied-thermodynamics literature, and it is particularly attractive today because large databases of thermophysical properties are widely available. This work presents some representative patterns of thermophysical properties related to fluid phase behavior and demonstrates their use to estimate missing properties, to identify those properties that maybe in error, and to teach these patterns to scientists and engineers.