Don't use family birthdays
This is a common trap. Obviously it lacks originality but more than that it reduces your chances of winning. Just think about it -- the days and months only go up to 31 and 12. Even if you do win using your birth digits, the chances are you'll have to split the winnings with more people. After all everyone's birthday begins with 19 (and anyone who doesn't should not be playing). The same applies to buying a ticket when there's a bigger jackpot -- more people play so the odds are more people win. Let's be honest you don't want to have to share with strangers anymore than you want to hear from your second cousin twice removed after a 20-year silence.