I stumbled across this useful hint on the Things forums which adds a feature to my workflow which I felt important enough to record here.
Most of my digital inputs come via email. It’s hugely useful to be able to (with a single keystroke) forward an email to my Evernote inbox, but being unable to do the same to send a task to Things was creating some friction.
The easy answer -
Any emails you send to your firstname.lastname@example.org account will appear in your Reminders on iOS, and will show up automatically in your Things inbox, ready for import.