Thinking about it though, it’s certainly easier to state what the goals should be rather than the specific no-nos that take away from reaching those goals (therefore, good question)…

I’d say some good rules of thumb (for goals, or what TO do) are to minimize the display of unnecessary information (which includes “snazzy” animations that don’t serve a useful purpose), make it as clear and easy as possible to perform a given function, and generally aim to make the user feel happy (yes happy) to use the application (which means a lot of things really, including having a pleasant aesthetic appearance, being responsive and snappy, and reliably performing the expected functions without error).

Happiness is pretty important in life, and I’d argue that it’s probably the #1 goal you should have in mind when designing an interface. Sure, the primary goal of software development is to produce an application that performs a certain set of functions. But what happens when that is not accomplished? The users get unhappy. Why not set out with their happiness as your primary concern. You’re bound to end up with a better product that way.

So anyway… some no-nos beyond what you already mentioned are… don’t present the user with cryptic error messages, don’t have a button that executes a function when clicked that takes a long time without giving the user some indication that something’s happening (and DON’T forget to make sure the user cannot then re-click the button), don’t use obnoxious colors or graphics or animations (it’s better to stick with plain old textboxes and buttons and no graphics than to get this wrong), and probably my biggest pet peave is when I go to a site that has media like a movie or sound file that starts playing right away without my having clicked “Play” somewhere (it’s startling to be surfing along nice and quite and all of a sudden some one is blaring at you… DON’T DO IT people!)

Hope my admittedly long rant here was sort of what you were looking for

Peace out.