Step One: Watch Mary Rose Cook Live Codes Space Invaders from Front-Trends. (The second worst conference name ever?)
Step Two: Fork this gist.
Step Three: Respond to this question in your fork: What is one approach you can take from this Mary's code and implement in your project?
I really liked her use of a game constructor that oversaw the main functions of how the game would be played. Makes her code very clear and easy to understand. Her use of a keyboarder object and way to implement collision detection were also cleaner than what I currently have in my game, and I'll look to model mine after hers.
Step Four: Totally Optional: take a look at some of the other forks and comment if the spirit moves you.