Perform actions on notes
In Sierra, you could two-finger swipe across a note to show a delete button (and continue dragging to delete the note). In High Sierra, the leftwards swipe still brings up the red delete button, but it’s joined by a grey lock button. Locking a note stops it from being edited. This action previously required a menu action.
New to High Sierra is the ability to pin a note to the top of the list. Two-finger swipe across a note to the right – keep going, or click the gold Pin button. Alternatively, use File > Pin Note, or the contextual menu. If you often pin notes, create a keyboard shortcut for Pin Note in the Keyboard pane of System Prefs.