Quote: "Make 2 lists - 1.0 and 1.1. Write your initial idea down on 1.0. When you think of something new once you've started, put it on the 1.1 list, for after 1.0 is complete."
^ I think that's a great idea. I'm exercising that now with my current project, and it seems to be working. I'm pretty much at 1.0. The 1.1 list is pretty big too.
I would also say, when you are deciding on what game to make, your game "world" needs to be small and finite, which will make it easier to fill and complete. Small games that can be made complete very quickly are best, cos you can then ram them full of more and more detail to make them rich, without the task being too much for you.
Also, you can ignore anything Cash says, as he is a superhuman game maker, so any advice he gives only applies to similar game dev superheros, of which there are none.
And finally, if you're struggling to stay engaged enough to make pong, you're screwed, so quit now.