Getting ideas is a fickle business. Sometimes, I'll be sitting at my computer for hours trying and failing to come up with some really cool concept. Other times, like now, I'll be literally flooded by them. I have so many papers surrounding my computers that it's getting ridiculous. Honestly.
First off, I have Outcasts to work on. I need boons and flaws and a basic list of powers and augments. But finding the time to work on it is impossible, with school and other fun stuff.
Second, I have a dystopian novel and romance novella sitting on my computer desktop waiting to be written, as well as a five-act play about Tristan and Isolde, and a screenplay about the aftermath of a school shooting. It's insane.
And now, I have another idea I want to implement, more along the lines of a classic dungeon-crawl, inspired by an hour long conversation I had with a friend reminsicing about our previous adventures.
Where does one find the motivation to even start whittling away at these?
Hmm...
The best advice I ever received was simply to do something.
I've actually found that 24 hour RPGs and one page RPGs are a good way to get your mind into the game making mindset. Most of these game's weren't exactly exciting or good in any way, but they did jump start the creative juices on decent projects.
Aside from that, Chainsaw Aardvarks suggestions are high on my list too. If you can get yourself into the mindset of the game you are trying to make, things will go far smoother than trying to force it.