Going to jump on the "yes, do it no matter what!" train because yeah, it makes photos look so much better. It is especially important if you're going to perform in the masquerade, because your face will look much better on stage with some good makeup.
I wish teenage-cosplayer-me from years back had someone to help her with makeup a long time ago! I used to only wear it for costumes that needed it because the character was clearly wearing makeup, but now I do it for all characters no matter what. Even dude cosplays!