This document is the culmination of several years of collaborative and cooperative work among a wide set of legal, scientific, and economic experts in industry, government, academia and more. The Best Practice Approach Frameworks presented herein provide unique step-by-step processes as to how one can approach four rather complex topics that are integral to the conduct of natural resource damage assessments under U.S. laws and may also be applicable to practices under EU and other liability regimes. The Frameworks focus on four salient topics—PFAS, Climate Change, Remediation, and Emergency Response. It is hoped that their application in site- and case-specific instances will aid consideration and decision making concerning these topics in the context of natural resource damage liability, assessment, and restoration. As the natural resources practice arena is a dynamic one, the Frameworks will be reviewed periodically for possible expansion or revision, and we welcome comments on them as well.