'Seven abominations' is a way of saying the wickedness in this person's heart is complete and manifold. The warning is clear: do not be disarmed by pleasant speech alone. Discernment means looking past the presentation to the pattern of a person's life and character.
Memory phrase: Look past smooth words.
Talk about it: How do you know if you can really trust someone?
Prayer: God, give me wisdom to see what is true.