According to standard textbooks on thermodynamics, first-order phase transitions occur abruptly at given values of external control parameters such as temperature, pressure, stress, or applied field (magnetic or electric). In ferroic materials, however, these transitions rarely show such an ideal behaviour. Commonly, the expected sharp change of the order parameter is smoothed out and thus the transition spreads over a certain range of the external control parameter. Even more, in most cases they proceed through avalanches. On the other hand, in a number of systems the transition is preceded by anomalies, typically detected in the response to certain excitations, which originate from the tendency of the system to perform anticipatory visits to the low symmetry phase. In my talk I will establish that disorder is an essential ingredient for these phenomena to occur. In particular, I will discuss the general requirements for pretransitional effects such as tweed to occur. Furthermore, the effect of disorder on the transition kinetics will also be considered. Specifically, the athermal character of the transition will be emphasized and the main characteristics of the complex free energy landscape due to the presence of disorder will be analysed. Finally, the dependence of hysteresis as well as avalanche behaviour on the driving rate (of an external field) will be considered. The results presented will be illustrated with examples for systems undergoing magnetic and structural transitions.