I always forget my rarely-used magical gestures/presses. I've had a 7+ for a good long while but only ever trigger that by accident. Couldn't have told you how to do it. Ditto Apple Pay.

[EDIT] I think part of why I haven't made it part of my normal use of the phone is that the shift-from-normal-one-handed-grip-to-double-press-home-then-back-again maneuver is risky (of dropping it) enough I'd shy away from it and just use two hands.