Don't level a profession right before a server restart.
I finally got around to creating a Death Knight yesterday, and after working through the starting zone I decided to stop off and level my herbalism a bit before heading to outland. I know the market for herbs is strong right now because of Inscriptions (which I'm also leveling), so that seemed like a good idea.
I was working my way through Elwynn Forest gathering up all the flowers I could. After I hit 75 herbalism I went back to train to the Journeyman level and pickup Apprentice Inscription. There was about 5 minutes left before the server restart, so I decided that I would sit there and mill some herbs and make some ink.