Some lessons I think any eco-city can learn from Copenhagen and Masdar City:
1) The importance to have specific targets that are set and monitored - such as Copenhagen's goal to have over 50% of inhabitants cycling to their place of work or education
2) For existing cities or districts that are trying to transform into eco-cities, the need to have a strong engagement with the community so they feel they are part of the solution and their needs and concerns are heard
3) Taking advantage of natural opportunities in your environment, for example if a particular city is more amenable to the use of solar or wind power (Masdar City has a lot of opportunity for solar power)
4) Looking at the best balance between energy generation (using clean renewables) and improved energy use (e.g. improved transportation - something that both Masdar and Copenhagen have focused on)
5) The need to look carefully at the human element - how can things be designed so that taking the most sustainable/green option is the easiest and most appealing - people do what is easy and good urban planning can gently lead people to better behaviours.