What is the best way to track individual worship attendance using a Connection Card

Have a dropdown with your services listed on the card, then use the auto-register feature to count them as part of that service.

Here are the steps to do this.

1. Create a group for each of your services including online ones.
2. In step 1 be sure to check the radial that this group is for "Adult Worship / Youth Attendance."
3. In step 3 be sure to answer the profile questions the same way for ease of reporting.
4. Create a "Connection Card" group.  
5. To the form fields on the bottom of the registration settings page, add a "Service I'm attending" custom registration field.  Be sure to set up each response to auto-register to the correct group.
6. Add the keyword you want people to text to get the link to register.

Now, all you have to do is create the communication content: a slide for the screen, an ad for your bulletin, and script for an announcement.  If you want to use a QR code you can do that too.