How Do I Create an Automation To Create a Task Based on the Completion of a Previous Task?

This Event-based Automation will automatically create a new Task once a Task of a different Type has been completed.

Prior to setup, create your custom Task Types.

Recipe:

Choose the "Event based" trigger type
Select the "Task" trigger record
Choose when the record type is "Created or Modified"
Select +Add Condition
1. If "Is Complete" is equal to "True"
Check the box next to "Only if Is Completed is modified"
Select +Add Condition again
1. If Task Type is equal to "[Select appropriate Type]"
Check the radio for "Require all conditions to be true"
Select +Add Action
Choose the "Create Task" action
Create your Task (giving it a Type that is different from the triggering Task's Type) and choose the assignees, then click "Save"
Save the Rule when you are finished

Note:

Do not create an Automation in which the Condition and Action contain the same Task Type without including some other Condition(s), as well. Doing so will cause an "Automation Loop".