Citizens Energy Communities (CECs) are a powerful instrument for promoting the energy transition, putting citizens at the centre, increasing energy efficiency and tackling energy poverty. CECs are a relatively new topic and the incomplete transposition of EU provisions for CECs into national laws is putting a barrier to citizens’ involvement. Beyond this, there is a lack of information and knowledge about regulation, technology and operations of CECs, urging the need for advisory centres to increase trust and raise citizens’ awareness on the benefits of energy communities. In this work, an analysis of how the development of CECs can be fostered will be carried out, using as a reference the experiences gained from the EU-funded LIGHTNESS project. In the LIGHTNESS project, pilot leaders have provided the citizens involved with guidance and training to become active users within the community. In order to involve users directly, energy services can be implemented, such as demand side flexibility, to facilitate the integration of new loads and renewables, and innovative financing schemes can be set-up, such as dedicated incentives or crowdfunding, which arise as participatory tools. Furthermore, the deployment of a dashboard, that shows users relevant insights on energy monitoring, proved that digitalization is a part of the engagement process. The aim of this paper is to fill the gap of the little attention given in energy projects to the evaluation of the impacts of citizens’ engagement process, using behavioural insights and smart technologies to find innovative approaches to engage communities in a just energy transition.