There is no 'best' way to be an advocate and no such thing as an 'expert' advocate. The situations in which an advocate might work are so varied and the strategies which might be used are so different that it is impossible to be an expert in all of them.
Consumers are people who use services, voluntarily or involuntarily.
This includes people with disabilities and those who care for them. As with any consumers, users of services for people with disabilities should have the right to choice, quality, accountability and redress. Advocates are people who have been given the power by consumers to speak on their behalf, who represent the concerns and interests of the consumer as directed by the consumer, and seek the outcome desired by the consumer. Although governments and others may give power to advocates, such advocacy is token unless it is directly accountable to the consumer. Advocates must have a separate, clear role.