Evangelism only happens when you verbally share the good news of Jesus Christ. And, even if the gospel is preached to a crowd, dialogue usually happens at some point. After Peter's Acts 2 sermon, they asked, "Brothers, what must we do?" If you never initiate conversations, then it may be a long time, if ever, before people have the chance to hear the gospel.

I am not suggesting that you be rude, pushy, or overbearing. What I am suggesting is that you initiate the conversation. What do you do if people aren't open or if people don't want to talk? You can't force them and you shouldn't try. But at least you have taken the initiative to begin a spiritual discussion.