This manual is based on findings from the implementation of the USAID-funded Rice Field Fisheries Enhancement Project (RFFEP) in four provinces of Cambodia (Kampong Thom, Siem Reap, Pursat and Battambang) between 2012 and 2016. The manual has been developed to guide relevant stakeholders and target communities in how to approach i) the selection of Community Fish Refuges (CFR) and ii) the process of designing and implementing improvements to the CFRs. It summarizes and distils lessons on how to design functional CFRs and followon interventions in order to improve the physical and biological characteristics of CFRs and their connectivity with the surrounding environment.