To me, the biggest lesson I've learn from game programming tips and tricks was to not model the world exactly. Just model it enough to trick the eye. My first inclination was, "but of course you need the splats where the rain drop line ends! How would it make sense otherwise?" But it's not until you see the video that you get that, hey that worked well enough. I imagine it's applicable to other realms of programming…
This can be used to add fancy animations, add an actual embedded video over an image of an empty video player, add comments to the end of a blog post via AJAX. Most people won't even realize you're giving them static content initially.