Encourage them to talk with God in their every day speech and mannerisms. You don't have to be a rocket scientist, brain surgeon or a monk to participate in conversational prayer. Emphasize authentic expression with God and one another. We have different styles and tastes when it comes to fashion, music, food or sports. You'll need to know who the people in your group are and be sensitive to their likes and preferences.
Some people prefer silence, some want music.
Other people are intuitive and prefer less structure, more spontaneity and imagination when they pray. You need to be aware of your style and others so that everyone feels included during conversational prayer. The place you meet for prayer influences the atmosphere for your group. It helps to have a regular meeting place that everyone can find easily, but don't lock prayer to one location. There's a practice known as geographical praying.