The Eclipse Graphical Modeling Framework (GMF) provides substantial infrastructure and tooling for developing diagram-based editors for modelling languages atop the Eclipse platform. It is widely accepted that implementing a visual editor using the built-in GMF facilities is a particularly complex and error-prone task and requires a steep learning curve. We present an approach that raises the level of abstraction at which a visual editor is specified. The approach uses annotations at the metamodel level. Annotations are used for producing the required low-level intermediate GMF models necessary for generating an editor via model-to-model transformations.