For starters, how about governing the country in a way that doesn't create numerous low-hanging opportunities for propaganda against it. You know: don't invade other countries, don't torture people or hand them over to allies who do it on your behalf, don't ally with countries who do all of the above, don't conduct mass surveillance on your own citizens etc.

To be clear, I'm not saying that the enemy agitprop is all true. However, the most effective kind of agitprop is the one that uses facts as the foundation for the rest of the structure. So how about we start there?