A small proportion of people claim to live and consume in ways they consider more sustainable in social and environmental terms. As yet, we do not know how many exactly, but possibly no more than 5-10% of the population. The thesis intentionally focuses on this minority finding there are at least three reasons why it is interesting to do so. First because they are all but ignored in sociologies of practice in the context of sustainable consumption which considers this minority an insignificance and focuses almost exclusively on 'mainstream' majority which more closely maps onto the stereotype of 'consumer society'. Second because we think we can learn much from juxtapositioning this group empirically against the spectrum of theories of practice to devise more robust and appropriate theoretical explanation of how these subjects, in the context of everyday practice, negotiate the many interpretations and contradictions involved in trying to put 'sustainability' into practice. Third because by understanding them better we can reflect on theoretical, empirical and policy implications for nudging this minority of the population to a higher percentage. The thesis sits at one end of a spectrum of positions in theories of practice applied to consumption, and in particular with a normative interest in sustainable consumption. It aligns with those who seek to re-insert the reflexive agent into accounts of practice, with particular reference to the conceptual construct of the 'citizen-consumer' and the context of political consumption (Spaargaren & Oosterveer 2010). Referring to theories of consumption, the thesis adds perspectives on how people negotiate multiple domains of consumption simultaneously since everyday practice involves interactions across multiple domains (such as eating, mobility, householding); and yet typically in theories of practice these are artificially separated into single domains. The study therefore considers the implications which domains have on how particular practices are carried out, first separately (per domain) and then as they come together (in a cross-cutting domain perspective). The study then takes theories of practice as a springboard to develop a theoretical position and framework which better fits the narrated accounts of the 37 subjects who participated in this study. In iteratively co-developing a theoretical framework and multiple 'stages' of empirical research (using grounded theory methodology) the study seeks to explain theoretically how subjects justify their 'doings' (drawing on 'conventions' and 'orders of worth' (Boltanski & Thévenot 2006)); how they appear to muddle through as best they can (introducing 'bricolage' (Lévi-Strauss 1972)); and how subjects appear to devise decision short-cuts when approaching decisions characterised by the multiple contradictions of sustainable consumption and incomplete or 'too much' information (introducing heuristics (Gigerenzer & Gaissmaier 2011)). In joining calls to re-insert the reflexive agent to account for how, when and why subjects enact changes towards trajectories which they consider 'more sustainable' in their own terms, the study takes inspiration from Margaret Archer's morphogenesis approach (1998) and explores her model of multiple modes of reflexivity, announcing certain modes as 'better fitting' conditions of late modernity. The study finally finds that contrary to a notion of the un-reflexive agent, the citizen-consumer is able to articulate visions of the 'good life'. In addition she is able to fold these visions back onto everyday practices performed in the past, present and future, laying out normative guidelines and positive accounts of how to achieve personal or societal well-being and happiness. The overarching positioning of the study is much inspired by Andrew Sayer's (2011; 2000) 'normative turn' calling upon social sciences to re-instate research into the things about which people care. The study is therefore guided by the overarching question of how people translate their environmental and/or social concerns into the ways in which they live and consume.