From Jonathan Snook:
Make the right things easy and the wrong things hard.
I like this idea from a user experience point of view. How many times have you thought “oh, this should be easy”, only to discover it involved hunting for three different hidden links, and filling out a form that required five times as many clicks and steps as it really needed.
When you find yourself thinking the number of clicks to accomplish a task could be easily cut in half, then you are probably not making the right things easy.
Looking at a single page or screen, ideally it would be really clear what we want the user to accomplish. If it isn’t clear, or if accomplishing it is significantly harder than doing something else, then it is worth rethinking your approach.
The developer version of this reminds me of Larry Wall on Perl:
Easy things should be easy, and hard things should be possible.
From a code point of view, hard things should still be possible. But the easy things shouldn’t be made more difficult because of those hard things.