Advocacy can take many forms and is more aligned with different spheres of society. The forms include lobbying, protests/demonstrations, strikes, petitions, boycotts, civil disobedience, ballot initiatives, and political campaigning. See also the other tabs of this guide for leads to some of these forms of advocacy - e.g. see Economic/Consumer Issues for information on boycotts.
There are many places that teach advocacy including the legendary Highlander Center which honed the skills of many famous advocates like Rosa Parks, Martin Luther King, Jr., and John Lewis.
Selection of sources below do not represent a political position but rather an example of good practice regardless of where one stands on the issues the rally is undertaking.
The idea of the public having direct input into government budgeting developed in Porto Alegre, Brazil. Recent AQmerican Political Science Association (APSA) task force report highlights its usefulness. Below are a few sources and sites to stay abreast of developments.
Journal of Public Deliberation - a special issue on the topic volume 8 no. 2 2012
Participatory Budgeting Practices, Places, games, and Resources - a nice set of resources from a blog by democracy activist and author, Tom Atlee
Participatory Budgeting Project - captures efforts going on in the US, Canada and around the world. Maintains an online library of material.
Participatory Budgeting Unit - a UK site that collects case studies and other resources applying participatory budgeting approaches.