Is there a good tic tac toe strategy for the second player?
As you know, tic tac toe is a solved game that end in a tie with optimal play.  And it's too short to really get any initiative as the second player, even for children.  Going second there is no way to force a win without 2 misplays from the first player.  So if you want a "strategy" for player 2, it really comes down to just not losing.  

As for going first, I often liked taking a corner first because it offers more opportunities for my opponent to mess up (any square but the middle is a win for the first player with perfect play).