Look at other great videos to have a starting point.
The modeling business uses an exercise called “Tear Aways.” These are the images that clients find in or "tear" from a magazine that embody the look and feel that they wish to portray in a shoot. You will now do the same but with web links and welcome videos.
Each member of the team will find 2 church welcome videos on the internet (any denomination) that contain messaging, imagery, music, or pace that speak to the vision or feel of your church. Each person will also bring in a 3rd video that is a marketing or advertising video from a secular institution.