The best time to pluck your brows is after a warm shower. Your pores will dilate and the hairs come out easier and less painful. The worst time to pluck your brows is after washing your face with cold water, since this causes the pores to shrink.
If you aren’t showering, soak a cloth in warm water for a few minutes and place it over your brows to open up the pores. Then, after you’re done tweezing, wrap some ice cubes in a cloth and place it over your brows to help close the pores faster.