Twin pregnancies pose distinct physiological, nutritional, and psychological challenges that require tailored periconceptional care strategies. This chapter explores the pivotal role of maternal lifestyle factors in shaping pregnancy outcomes and synthesizes current evidence on key components: gestational weight gain (GWG), nutrition, physical activity, and mental health. While promising twin-specific guidelines are beginning to emerge, significant gaps in knowledge and clinical recommendations remain. Much of the existing guidance continues to be extrapolated from data on singleton pregnancies, which may not fully address the needs of women carrying multiples. The chapter reviews current GWG recommendations for twin pregnancies and frames nutritional guidance in light of increased energy needs, examining both macronutrient and micronutrient requirements. It also highlights the benefits of physical activity, outlines the current recommendations, and explores the consistently low levels of engagement in exercise among women with twin pregnancies, despite its known advantages. Mental well-being receives particular attention, with a focus on the heightened risks of stress, anxiety, and depression in twin gestations, along with a detailed discussion of evidence-based interventions such as mindfulness, cognitive behavioral therapy, and social support. Finally, the chapter presents clinical data supporting the effectiveness of lifestyle modification programs and emphasizes the urgent need for research dedicated to developing robust, twin-specific care models. Beyond offering practical recommendations, this chapter seeks to raise critical questions and encourage healthcare providers to embrace a holistic, multidisciplinary approach to supporting women with twin pregnancies–starting as early as the preconception period.