For a while I was just copy/pasting a previous entry as a starting point for a new post. That was tedious, and I missed the meta data that Day One included in a post by default, primarily location and weather. So, I put together a Workflow script to create a new journal entry in Ulysses for me.
Here's what it looks like on my iPad:
The version that includes weather requires an API key from Dark Sky. While free, not everyone is up for getting an API key just to create a journal entry, so I've created a separate workflow for sharing that doesn't use weather data in the post template.
In order to use either workflow, you'll need a top-level group named "Journal" in Ulysses.
You can grab either workflow here, if they'd be of use to you: