Setting one of your services as the 'default' is easy!
TIP: If your default service is self-scheduleable, your customers will save clicks when booking online but they might accidentally schedule the default service without realizing it. Disabling self-scheduling for your 'default' service will save you clicks when booking appointments and will require your customers to select all their services when self-scheduling online.
FROM THE WEB APP
Step 1: Go to Settings > Master Service List
Step 2: Click on an item in your master service list.
Step 3: Check the "Select this item by default' box
Step 4: Save
FROM THE MOBILE APP
Step 1: Tap Menu > Settings > Master Service List
Step 2: Tap on an item in your Master Service List.
Step 3: Check the "Select this item by default' box
Step 4: Save