I always say something as first player. I know several players who are allergic to "good luck" in games where luck plays no part. I try to remember them and open with "have fun" or even "hi, how are you". I remember one player who became obnoxious after a "good luck" so I answered with "fine, may Fortuna smile upon your feeble endeavours" or something like that. he's one of the very few players who chumped me, I didn't cry.