Finding models that show promise has been more difficult. My investigations eventually led me to the following sources of inspiration: indigenous socieities, the very earliest civilizations, the anarchist literature, and certain group-facilitation processes. From these inspirations, I arrived at two principles which are, I believe, the core principles of genuine democracy.
The first principle: Harmonization
This principle is about decision making, and how conflicts-of-interest are to be resolved. In our societies today, conflicts are resolved by means of power: the most powerful faction gets its way. It's a win-lose system. People join parties or special-interest groups in order to have some hope of exerting influence in society. Harmonization is about resolving conflicts through respectful dialog. It is about taking into account everyone's concerns, and coming up with plans and solutions that deal fairly with all those concerns. Harmonization is not about choosing among alternatives, rather it is a creative, problem-solving process.
The most surprising thing about harmonization is that it is possible. For most of my life, I assumed such things weren't possible. When I thought of political change, I thought in terms of "us progressives" overpowering "those conservatives" - an adversarial approach. I then had the privilege of experiencing harmonization in some interactions with groups, and that opened my mind to new possibilities. I then looked more deeply into facilitation processes, and learned that harmonization is practically achievable, even in groups with strongly conflicting views. I also learned that harmonization is an ancient and venerable tradition, used for hundreds of thousands of years by indigenous societies. Divisions between "right" and "left" are not nearly as important as they seem: they do not reflect different economic interests, or even different visions of what would make for a "good society," but are more a reflection of different responses to propaganda.
The second principle: Localism
This principle is about the seat of sovereignty, and the extent of sovereignty, in a democratic society. This principle arises from the nature of the democratic process. In order for a group to operate democratically, it is necessary for everyone in the group to participate in the process. That is to say: scale is important - size matters. In a local community, by means of something akin to neighborhood meetings, it is possible to establish a genuine democratic process, based on harmonization. The city-states of classical Greece provide useful models in this regard - although we must also take into account that those were slave-based, male-dominated, imperialist societies, and the dialog process was more debate oriented than harmonization oriented.
From these and other considerations, I've been led to the principle that the local community needs to be the basic sovereign unit in a democratic society. For this purpose, a community is "just the right size": large enough to be a viable political entity, and small enough that it can operate on the basis of an inclusive democratic process. Within a community, everyone's voice is heard, and everyone's concerns are taken into account - by means of harmonization processes. Similarly, within a region, each community's voice can be heard in regional councils, and each community's concerns taken into account. And so on, up to global councils, also operating by means of harmonization. No permanent seats of government are needed, which would help avoid the emergence of heirarchical power centers and ruling elites.