This publication highlights the importance of carrying out advocacy strategies as instruments to bridge the gap between science and policy, on one side, and to enhance citizens participation in the decision-making process, on the other side. Practical guidance is provided for the development and implementation of such a strategy through the description of a step-by-step approach. In the first place, it is recommended to conduct a diagnosis of the problem, in order to design more effective solutions. Secondly, an analysis of the decision-making environment needs to be undertaken to determine whether and how citizens have an opportunity to influence policies. This should be followed by the selection of the advocacy issue, audience, channel of influence, and, last but not least, the identification of allies and opponents. The final phase includes the establishment of a workplan listing all the actions to be performed and the actors in charge of them, duly complemented by evaluation and monitoring schemes.