For me, there’s pressing hard on the X in notifications to clear them all at once and hard pressing the icon on the Eva app to open the quick actions menu and choose to start the climate control in my Nissan LEAF before I leave the office.
3D Touch on the Phone app’s icon to get quick access to favorite contacts.
3D Touch on the Drafts icon to quickly jump to a recent draft.
3D Touch to move the cursor in text and
to “Clear all” notifications in lockscreen.
Yeah, moving cursor and selecting text is something I use probably hundreds of times a day. The main reason I can’t get an XR!
Another good one is 3D Touch in control centre timer to quick-set a new timer. And on Control Centre’s Do Not Disturb button for timed and geofenced DND activation.