One of the things you can implement to boost evangelism in your church is to do events. They can be purely social and community events that promote good will to give you an opportunity to share the gospel at a later time or they can be more overtly evangelistic that clearly share the gospel. The options are literally endless and I think the church can learn a lot from groups like Campus Crusade in sharing the gospel to strangers and pulling off events. I would also commend to you Alpha. If you have never looked into Alpha, you must. It's a great tool to explain the basics of the Christian faith in a very relational, non-confrontational way.
Another great benefit of doing events is that it gets the "evangelistic blood" flowing in your church. If you feel like you're in a dry season evangelistically, your people may need a moral boast and inviting people to an event is an easier ask. While you may not be able to get a bunch of guests to your Sunday meeting, you might be able to get a bunch to an event. Having this kind of success can give your people a vision for more evangelism. What you ultimately want is evangelistic momentum like you see in the early church (daily additions), but sometimes you have to start slow and take smaller steps to get that momentum going. Doing events could be your church's next step.