I am looking to make a zero line staff so that I can make pages look like the early part of a piano method, where the notation only has fingerings and suggests direction, rather than specific notes.
The closest I can get to that is a single line percussion staff, or deleting the staff all together, but then I can’t input notes. Anyone have any ideas?
Welcome to the forum, zutzutriot. At the moment there’s no good way to produce an instrument with a zero-line staff, I’m afraid.
Although you can’t do this within Dorico, a user shared an XML file in the Dorico Facebook group that contains an instrument set up not to show staff lines - it’s in the Files section of the group, and it’s called “0line.musicxml”. If you search “0line” in the Facebook group you’ll find some explanatory comments 
I tried 0line but the problem is I need it to be within an existing document, and you can’t export it into anything 
If you import 0line.xml as a new flow in your existing document, you will have the instrument added to your project. Then you can add it to the other flow(s) in Setup Mode, and finally delete the imported flow.
This isn’t gonna be officially supported, but take an instrument you never use, and hack the instruments.xml file that can be found in Program Files/Steinberg/Dorico 3. Make a backup first, but just change the line for “numStafflLines” to 0 and it will work for that instrument too.
this worked like an absolute dream; thank you!