Every time you move a piece over, the game counts it. The more you move it, the game thinks you have more trouble with that certain piece, and will dish out more of them. You can exploit this every time you get a Tetris (Long "I" shape) piece, just move it from side to side as it falls. You will get it more often every time that you do so.
Press select while playing a game to hide the preview of what block is going to fall next.
Start the game and wait for the demo. When the computer eliminates the four lines at once (makes a tetris), and the screen begins to flash, press start. Now start a B-type game. The screen will flash, and you will start with extra points plus 4 less lines to eliminate.
While playing, hold Select to stop the pieces from falling and thus, giving you time to think.