You want the hearer of your message to see and know you are personally talking to them. So look them in the eye when you preach.
Don’t do the following when you preach: look over the people’s heads or at their feet or wear sun glasses or a cap that covers your eyes.
If your crowd is passing by like at a game, festival or campus make the effort to look as many of them in the eye as possible so they will see you are talking to them.
If you crowd stops to listen to you look them in the eyes. Scan the crowd back and forth as they listen but don’t lock your gaze onto one person isolating them unless they are asking questions.
Don’t preach as if you are disconnected from the people. You are a living soul and so are they so preach them as a fellow living soul who is able to receive your message.
Don’t yell and scream in an impersonal way.
Extreme examples of preachers always make the news but the faithful preacher who cares for the passing souls, see 2 Corinthians 5:18-20, Titus 3:1-7, is the one who pleases the Lord and sows and waters fruitfully.