Templates are a great way to have recurring prompts for consistency journaling. These are available in version 4.2 on iOS. In version 4.3 on macOS, templates are available to add to entries. Creating and editing templates will be in a future iteration of Day One Mac.
There are curated prompt options and ways to create and customize your own. These can be used with Reminders or they can be called up independently at any time.
To start a new entry with a template, tap the + icon at the bottom of the screen and choose Templates. Frequently used templates will appear at the top.
Choose an existing template or edit/create a new one. You can even edit the existing templates to fit your needs.
Templates can be edited from the Settings menu as well. Tap New Template to create your own. Use Add Section to insert headers. You can also use the Aa text formatting menu to add rich text options, checklists, bullets, etc.
While editing an existing entry, templates can be added by tapping the Paper Clip icon and tapping Templates.
Templates can also be activated with Siri Shortcuts.