From a software dev who went to school for graphic design, this is pretty spot on. I'd tack onto that plan ahead, that making paper prototypes, even lo-fi ones, help that step quite a bit. You get a better understanding and even at that point, you could have people test it out by asking them what they would do to try to do X Y or Z on your app or site even though it's on paper. It's helped me a lot with past projects. This is if you have the time to do this anyway *