My buddy has a wallpaper on his phone that says, in large letters, "Do I really to be picking up my phone right now?"
Done and done.
I prefer this method too, as it helps me develop my self-control. (I have "τῶν ἐφ᾽ ἡμῖν καὶ οὐκ ἐφ᾽ ἡμῖν", which is from Epictetus and means "things that are up to us and things that are not up to us" as a reminder that I can exert control over my phone use).