[sixtofour]

"IV) Use the Intel Model. Do not have one product that you iterate on indefinitely. Rather, start over from scratch every so often. ... Intel learns its lessons and carries them over in spirit to the next model each and every time. Even though they start designing the implementation from scratch each time, they in essence remember the important bits from before, and have a Science for reproducing their implementation from their principles and learned lessons."

The whole article is worth thinking about, but this is the gem for me.