Charles has been involved with a number of cities or organizations in deeper and more prolonged relationships over many years based on trust. The most extensive have been with Helsinki, FORM in Perth, CEOs for Cities in the USA, a series of Albanian cites and Osaka. Charles is sceptical about traditional consultancy where the outsider assesses a situation, delivers a report and then departs - he is more interested in being a ‘critical friend’ to a city.

He has worked with Helsinki City Council's research department for over ten years. Starting with the development of a cultural strategy for the city, this extended to helping Helsinki gain its European Capital of Culture status in 2000; later he evaluated the impacts of that year. He has also worked on a public partnership to raise resources for cultural initiatives. Helsinki is now undertaking an Intercultural City case study and the city previously took part in Comedia's research on the social impact of the arts and the initial studies on the creative city concept.

Since 2006 there has been a close relationship with FORM in Perth, which resulted in Charles becoming their first ‘Thinker in Residence’. FORM is an innovative organization led by Lynda Dorrington that originally was the peak body for crafts in Western Australia. Over time it has morphed into a creativity organization with extensive links to the private and public sectors to develop path breaking projects and drive the city forward. It sees itself as a cultural change agent that works to stimulate WA's competitiveness and creativity through physical, attitudinal and systemic change. Its Creative Capital programme brings together thinkers and doers from around the globe, such as Al Gore, Richard Florida, Carol Coletta and Charlie Leadbeater.

‘CEOs for Cities’ is a bipartisan, non-profit alliance of US mayors, such as Chicago, New York, Boston and Seattle, corporate executives, university presidents and non-profit leaders, that works with local and national governments. It tracks urban innovations and has an extensive research programme that look at how and why cities become successful. Its City Vitals indicators have had a significant impact. Charles has worked with Carol Coletta, who leads CEOs for Cities and also produces the Smart Cities syndicated radio programme, since 2003. He has written two publications for them: Letters to urban leaders in 2005 and in 2007 The competitive platforms for ambitious global cities.

In 2003 with Pro Helvetia and the Swiss Agency for Development and Cooperation Charles created an experimental three year creative cities programme in Albania, which has now been extended. Initially focused on Shkodra and Pogradec this has broadened to another six cities. PH and SCP have funded the programme to explore innovative approaches to problem solving. The aim here is to use difficult urban situations, such as waste, degraded buildings, homelessness, youth disenchantment to assess whether creativity and the arts can help.

In 2003 Masayuki Sasaki, a creative city specialist in Japan, set up a Graduate School for Creative Cities in Osaka. Since then Charles has attended their conferences and run workshop with their post-graduate and adult students involved in professional development.