Innovative user interfaces are probably lousy, no matter how sensible or well thought-out they may be, because by definition they break the cardinal rule of usability – analogy to something the user already knows.

It’s much better to bring a better conceptual metaphor to a problem set than to build a better UI widget that doesn’t quite work like all of those other not-so-innovative UI widgets.

You’re a plumber, not Picasso. Your UIs aren’t a canvas – their point is to move crap around.

A few special apps can violate this rule – odds are, yours isn’t one of those.