The best thing to do is listen to the sound that real
Hens make when they are relaxed or at least listen
To a tape of some real hens. Then try to duplicate
Those sounds with your box call. All hens sound
A little different, so the exact sound as long as it
Is reasonably close is less important than the
Rhythm of the call and how frequently you call.
Generally speaking calling less is better than
Calling more, exception to this is when another
Hen gets excited and starts a conversation
With, then try to say the same thing back
A little louder than she is talking. If your
Lucky she'll get mad enough to come find
You and hopefully bring a Tom in tow.

Good Luck