Measuring patterns of tobacco use has typically involved assessing number of units and frequency of use of cigarettes. With the emergence of new types of products (e.g. e-cigarettes, water-pipes, heat-not-burn products), use of more than one tobacco product is increasing in popularity, and therefore quantifying the overall tobacco consumption of individuals is becoming more challenging. Novel products are different in design and consumption to cigarettes and their availability results in multiple and complex combinations that make the measurement of exposure to tobacco and nicotine containing products intricate. Moreover, these complex patterns of use present a challenge when assessing changes over time and evaluating their subsequent impact on health outcomes. Changes in patterns of tobacco product use over time (i.e. moving between different tobacco use status and combinations, the possibilities of single, dual or poly product use, progression from occasional to regular use, initiation, cessation, switching, and re-initiation between products) can be characterized by estimating the probabilities of transition between one tobacco-use state and another. This contribution presents an overview of analytical approaches to assess transitions in complex patterns of tobacco use. It addresses the practical implications of applying these analytical approaches across existing epidemiological surveys and datasets to characterize patterns and determine probabilities of changes in tobacco use status. In addition, it considers the utility of transition probability methods to provide a snapshot into changes in the patterns of tobacco use and how this can be used to inform future tobacco use trajectories, associated health outcomes, and tobacco harm reduction efforts.