This evaluation by PB Partners describes the process, achievements and learning from a participatory budgeting initative in Aberdeen where young people had their say on how £50,000 of underspend.
The report goes into detail about how the PB activity was carried out including media coverage, evaluation methodology and future recommendations. The report notes that:
"Whilst this project was untypical in some ways (ie delivered exclusively through schools and with a young voting demographic), for PB to embed itself at community level, best practice would involve the creation of a steering/planning group, comprising resident / community voices, elected members, and partner organisations, (particularly from the third sector)."
You can read the report here.