My point is, pay attention to your brows! When you go up on stage, you want to make sure every part of you looks the best it can. If you are unsure about how to tweeze or shape your brows, go to a professional. Attending to this seemingly small detail can make an enormous difference in how you are received.
If you insist on trimming your brows yourself, make sure to use your natural brow shape as a guide, trimming any hairs which extend beyond this shape. Plucking those hairs in the center is a MUST as well.