Simplicity is not the absence of clutter, that’s a consequence of simplicity. Simplicity is somehow essentially describing the purpose and place of an object and product. The absence of clutter is just a clutter-free product. That’s not simple.
The quest for simplicity has to pervade every part of the process. It really is fundamental.
The philosophy of Jonathan Ive (Apple’s head of design) when it comes to simplicity is something I totally agree with. Knowing ones purpose (or the purpose of something) is indeed central to and the first step towards simplicity.