A "double" means reaching double digits (10+) in one of the following statistical categories: points, assists, rebounds, blocks, or steals.
A "triple double" means doing so in three such statistical categories.
Adjusting offensive sliders upward for player shooting will help boost your points. Passing off to another player to make the shot will help boost your assists if he sinks the basket.
Adjusting defensive sliders upward, and CPU offensive sliders downward, will help improve your chances of grabbing rebounds from missed CPU shots, as well as making blocks. You can also improve your chances of making steals by adjusting penalty sliders down.
Increase the length of the quarters if you need more time to reach your doubles. Points, assists, and rebounds are probably the easiest to rack up, followed by steals, and finally blocks.
The Achievement will unlock once the game has finished.