Generally speaking..
Orlando Contreras wrote a three part article on Dominoes: Game and Theory. It was in the La Informacion some time ago.
In theory, you should try and 'kill' your opponents play by placing another number on what he left; help your partner by putting the same number he left, if it was 'killed' by the opponents; and lastly simply lay down the doubles you get.
Generally speaking, again, five doubles in one hand will nullify the hand.
Learn to count to seven, the number of dominoes of any one number: 0/0, 0/1, 0/2, -0/3, 0/4, 0/5, 0/6. After all, there are only 28 in a game. Cuban-style domino goes all the way to double 9...
Some times, guys have "secret" signals, like slamming down the domino to say: "Come again", or spinning a domino. These are frowned upon in competitive circles and have caused deaths...
HB