If you sell perishable products, then it is a must to use replenishment workflow. Replenishment workflow allows you automatically send email notification if contact didn't repurchase after a brief period.
Setting up Workflow
Select Workflow Playbook
Go to workflow playbooks page and select Replenishment playbook.
Select Trigger (Step 1).
Specify Days Interval. This is the number of days to wait after last order before you send replenishment trigger is fired.
Select Email (Step 2) and add new email with using template "Replenishment" email template
Click Submit to create workflow. That's it, setting up Replenishment Workflow is easy when you are creating from playbook.