Good, very concrete communications with examples of exactly how much of a difference an individual can make to prevent people from feeling overwhelmed and like they can't make a difference on the issue
To provide practitioners with useful information about how to promote proenvironmental behavior (PEB), a meta-analysis was performed on 87 published reports containing 253 experimental treatments that measured an observed, not self-reported, behavioral outcome. Most studies combined multiple treatments, and this confounding precluded definitive conclusions about which individual treatments are most effective. Treatments that included cognitive dissonance, goal setting, social modeling, and prompts provided the overall largest effect sizes (Hedge’s g > 0.60).
The results lead to some useful messaging recommendations, such as active publics being more effectively moved to action through motivational frames, rather than diagnostic (i.e. problem-focused) or prognostic (i.e. solution-focused) frames.
A negatively framed message (i.e. which describes the behavior that should not be done) is more effective, at least in this context, than a positive framed message that describes the preferred behavior.
Anyone interested in influence should start by focusing on the environment of the individual they are trying to affect. Analyze that environment and find ways to make desirable actions easy and undesirable actions difficult. Remember that the human cognitive system aims to get the best possible outcome for the least possible energy cost.