I think if people can clearly identify even the more obvious misinformation campaigns by foreign powers targeting them that would already help a good bit.
We should make Manufacturing Consent and The People's History of The United States mandatory reading for high school students, but that would probably change too many minds against our own system as kids would know how things really work, and how history really happened instead of the wishy-washy 'everything wasn't that bad!' crap they teach in grade school.