One of the favorite lines of attacks by cointelpro / disinformation / government trolls against the alternative media icons like Alex Jones and David Icke is that they have an <insert label here> agenda as part of a campaign of disinformation and confusion.
Even if these messengers did have an agenda, the general public can look at the message on its own as it is and see if there is any logic or evidence to the statement or information made by the messenger, without letting the affiliation/personal opinion/faction allegiance of the messenger color the message.
The key is to avoid mass media and other sources that influence knee-jerk responses or tell you how to think. Knee-jerk responses don't require critical thinking, which takes up time and energy, which is why many do it.
Shutting off the TV and reducing mobile phone usage to sms texting is a start.