One of the best ways is by giving an example, and making people aware of the damage caused by plastic on Earth, teaching everyone that they should not throw garbage on the street, doing cleaning campaigns, teaching with children and adults. Organization of cleaning days, giving talks to people in different institutions about the damage of this pollutant and many others; At the time they were created, they have done a lot of research on how to remove the plastic or reduce its use; However, it is not enough with that, we must make people aware of the great problem that this represents, the consequences that it brings, and that each person manages to take care of their own waste in a correct way, the main thing is the education of the human mass, that they understand that if this planet dies, therefore, possibly we too.
Invited @stanestyle a comment.