That's quite interesting. I'm reading design of everyday things right now, and has been very valuable for my product (SaaS,drag/drop). Not actually to build it,

That's quite interesting. I'm reading design of everyday things right now, and has been very valuable for my product (SaaS,drag/drop). Not actually to build it, but designing parts.(mockups etc) A lot of it is common sense, but only in hindsight.