I go to a salon once a month or so to make sure I keep the shape I want and then pluck on my own every few days. I just pluck the hairs that are clearly growing out because I have messed up the shape of them with over plucking many times. I also have one of those lighted magnifying mirrors to see the little hairs growing out.
I always thought that I had good eyebrows and that I didn't need to pluck until a makeup artist told me that I had uneven eyebrows! I never noticed it because it was subtle, but now looking back at pictures, you can tell! I just thought my face was shaped that way. Anyway, now I look more symetrical which has totally changed my face.