Here's a trick I like to use in teaching.When a student is struggling to lock in the right pitch, I sometimes have them purposely start out of tune with a given note (such as a tuning drone) and then slowly gliss towards the right pitch.
Sometimes, as they approach the right spot, they aren't sure if they've quite gone quite far enough. I tell them, "Keep going until you know you've gone too far, then turn around and go back to the pitch. Like a boomerang."
Somehow, going beyond and coming back seems to help a great deal.
This drawing represents a boomerang from below the pitch...
Of course, you can also do boomerangs from above.
