The failure mode of business automation is automating something interesting instead of something repetitive. Interesting work usually has exceptions, and exceptions are what break automations.
A good candidate has three properties: it happens often, it follows the same steps every time, and a mistake is recoverable. Enquiry routing, appointment reminders, invoice follow-ups and data entry between two systems usually qualify.
Start by writing the process down. If it cannot be written down clearly, it is not ready to be automated — and the act of writing it down often delivers most of the benefit on its own.