Your best source of inspiration for RPGs?
I have this nasty habit of eavesdropping. Whether I'm in public transit, in a family reunion, or with friends, I like listening to people tell stories and how they inject their own points of view of things into the story. Heck, when I was young, my mom's barkada (whom I will now affectionately call the titas) used to lament how I was always within earshot and therefore they couldn't tell my mom their juicier stories.
They eventually got used to me though, and so I heard things that no 12-year old should hear. But I digress.
Anyway, one of the things that I have internalized through listening is that you only get a small window to peek into what it is they're talking about. Far too often the info is biased, or imprecise, or told in a way that puts the storyteller in the best light. So I don't know exactly what is going on, but on the other hand I usually see just enough to speculate. My speculations are usually incorrect, hah.
Anyway, I feel like NPCs characters encounter in their stories are mostly the same. The motivations that justify what they're doing are rarely put in the limelight (this is the player characters' story, after all,) but they are there and it makes them the hero of their own story. Haha I am probably rambling here, but basically I like to think that by listening to people I am able to craft NPCs that are more than just cookie-cutter. And to me this is a huuge part of what makes my RPG games tick.
An aside: I also do a lot of research into Philippine culture and folklore, as anyone who's visited this blog before knows. And whenever I make Filipino-themed games, these things are pretty helpful as well. But to me the NPC creation takes the top spot.