Create a post
Type distill::create_post("Example post") and the folder is set up with the date run in the name in the folder _posts 
There are further details on posts on the RStudio {distill} site.
Knit the post
Once the post has been created, knit this to create an html page by either using the Knit button in RStudio (a ball of wool with needles icon) or typing the shortcut keys Ctrl + Shift + K .
GitHub Actions
Although the GitHub Actions build the site automatically, it does not extend to creating the html from the Rmd files as an action would have to refer to a particular file name which changes for each post. See the About page for more information on the building of the site.
Preview picture
The picture listed in the yaml called img/Lincoln's-Inn-Fields-and-the-localities-adjacent-p264.jpg shows up in the main page. This particular picture is from the British Library and has no copyright restrictions. Other commons copyright pictures can be found through Jenny Bryan’s GitHub repository free-photos.
Colour and font
NHS branding recommends using Arial as the secondary font. The primary, Frutiger, is paid for so is not used in this site.
The colour of the band is from the NHS colour branding from Level 3: NHS support greens.
Both settings can be found (and changed) in the styles.css file.