Coding Backwards

Now this is a really cool idea how to get a gerneral idea of the design you really need (and this is NOT the design that comes to your mind FIRST):

"I decided that I’d [...] write out a script using the yet unwritten API. I’d reverse-engineer a good design by pretending I’d already written one!"

"A better design quickly appeared when I forced myself to preemptively eat my own dogfood. Instead of shoehorning use-cases into a class structure I’d already designed, I coded backwards and the opposite happened: a design evolved from daydreaming about an API that I’d like using."

SOURCE: http://jameso.be/2011/08/19/coding-backwards.html