Tweezing is not effective as much as the other ways. It just pulls out the hair. I am not sure about threading but waxing pulls the whole hair out and it takes a long time to grow back. And each time there are less hairs to take away. And waxing grooms the brow to the proper shape.
You would be surprised the difference it makes on your face to have it done correctly. It takes years off and looks like you had an eye lift.

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