Start from the emtpy game template
Here is how your games looks by default when it has just been created :
Setup the board
Gather useful images for the game and edit them as needed. Edit .tpl & .css to add the board :
Setup the backbone of your game
Edit .sql to create a table for intersections. Edit .game.php->setupNewGame to insert the empty intersections (19x19) with coordinates into the database. Edit .game.php->getAllDatas to retrieve the state of the intersections from the database. Edit .tpl to create a template for intersections (jstpl_intersection). Edit .js to setup the intersections layer that will be used to get click events and to display the stones. Use some temporary css colors on borders or background+opacity to make sure they are positioned right. You can declare some constants in material.inc.php and pass them to your .js through .game.php->getAllDatas for easy repositioning.
Manage states and events
Remove temporary css visualisation helpers : looks good!
Implement rules and end of game condition(s)
Implement specific rules for the game (if any) Implement rule for computing game progression in .game.php->getGameProgression() Implement end of game detection and update the score according to who is the winner in .game.php->stCheckEndOfGame() Notify the score and implement the corresponding interface update in .js
Test everything thoroughly... you are done!