Significant progress in ontology engineering during the last decade resulted in a growing interest in using ontologies for industrial applications. This paper presents lessons learned and recommendations for ontology engineering projects with focus on industrial applications. The research is based on the analysis of a number of case studies in different industrial domains. Based on the case studies the paper presents experiences from ontology development and gives recommendations for industrial ontology construction projects. The recommendations concern (1) selection of development methods, (2) perspectives on generalisation/specialisation strategy, (3) aspects of user participation in ontology construction and (4) effects on knowledge management in organizations.