We have produced a digital "Checklist for high-quality implementation" as an aid to the practical work of implementation. The checklist, which consists of four overarching phases and fourteen critical steps, is based on a synthesis of 25 theoretical frameworks for implementation. The checklist starts with three key questions: "What need has been identified?", "What method is to be implemented?", and "To what extent does the method have scientific support?" Note that the ten first steps (Phases 1 and 2) are about planning, i.e. about thinking in advance. The actual implementation, following up and learning for the future do not feature until the final four steps.