Effective conservation of forest biodiversity and effective forest restoration are two of the biggest challenges facing forest managers globally. I present four general principles to guide strategies aimed at meeting these challenges: (1) protect and restore populations of key species and their habitats, (2) conserve and restore key attributes of stand structural complexity, (3) maintain and restore natural patterns of landscape heterogeneity, and (4) maintain and restore key ecological processes. The complexity associated with these principles is that how they will be practically implemented on the ground will invariably be ecosystem specific as what constitutes stand structural complexity or landscape heterogeneity will vary between ecosystems. Here I demonstrate the practical application of the four general principles in a detailed case study of conservation and restoration in the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, south-eastern Australia. These forests are characterized by declining species, loss of key elements of stand structural, loss of old growth forest, altered patterns of landscape heterogeneity, and altered ecosystem processes. I highlight how altered management practices in Mountain Ash forests that are guided by our four general principles can help conserve existing biodiversity and underpin effective forest restoration. Consideration of our general principles also can identify policy deficiencies that need to be addressed to enhance restoration and biodiversity conservation.