Rooney signed up last week.
"Greater contact with the public can be a good thing if you're not being perceived in the right way," Clifford told the Observer. "Wayne Rooney's the proof of that. If I was doing public relations for Manchester United I would be delighted he was showing himself to be different to the way he's perceived. This is his best way to show what he's really like.
"Twitter makes players more up to speed with what people are saying. They can respond to that instantly. It also gives them freedom to respond to stories in the newspapers. It's almost impossible to get a tabloid to print an apology or a retraction for a story that's a load of rubbish. Because of the vast amounts of people using Twitter players can now respond straight away, and if they're clever even name the journalist responsible."
Clifford points to Rio Ferdinand as an example of how to master the medium.
"Rio Ferdinand is older, more mature and he's looking to his own future career. He understands the importance of popularity as a marketing tool."