Driven by public awareness and international regulations and standards, sustainability and environmental impacts have become increasingly important distinguishing factors between competing products and services. Circular economy aims to increase economic growth by using natural resources and ecosystems in a more effective way with the aim of maintaining products, components and materials at their highest utility and value at all times. More effective use of materials enables the creation of more value both by cost savings and by developing new markets or by developing existing ones. Reduced acquisition of resources is a driver for innovation for sustainable use of materials, components and products as well as new business models. This chapter introduces methods and tools to assess and reduce environmental impacts, and improve resource efficiency and sustainability management. Life cycle thinking forms one of the basic principles of sustainable development, and Life Cycle Assessment (LCA) is the leading method for assessing the potential environmental impacts of a product, process or service throughout its life cycle (ISO 14040-44). Other methods based on life cycle thinking are also introduced. LCA focusing on the contribution of a product or service to global warming uses methods for Carbon Footprint measurement and facilitates the tracking of greenhouse gas (GHG) emissions (ISO 14067). Water footprint is a tool that assesses the magnitude of potential water-specific environmental impacts of water use associated with a product, process or organisation. It aims at describing the impact of water utilization on humans and ecosystems due to changes in water quality and quantity (ISO 14046 Environmental managementWater footprint-Principles, requirements and guidelines 2014). The concept of handprint has recently been introduced to measure and communicate the positive changes of actions and the beneficial impacts created within the life cycle of products, services, processes, companies, organizations or individuals. A handprint of a product can be created either by preventing or avoiding negative impacts (footprints), or by creating positive benefits. When adopting the circular economy way of thinking, companies need these tools and methods to ensure resource efficiency, cost cuts and improvements in their environmental performance which provide them with more earning opportunities. Fundamental changes throughout the value chain, from product design and production processes to new business models and consumption patterns, support this trend.