In addition to collecting gratuities during online bookings, or afterwards (in your Control Panel), you can allow customers to add their own gratuity after their event.
Collecting gratuities directly from your follow-up emails:
Customers who click "Add Gratuity" can choose a percentage, or enter their own custom amount:
Then they simply enter their payment info to complete the transaction:
For your security, stored cards can't currently be used with this workflow, but we may allow that at a later date.
Enabling this feature:
We've added a new Gratuities section to Admin->System Configuration, where you can enable this feature and customize the text that appears in the email: