Be clear and specific in what an option will achieve: for example, use verbs that indicate the action that will follow on a choice (see: Impl. 1).
Use obvious default actions appropriate to what the user needs/wants to achieve.
Fit the appearance and behavior of the UI to the environment/process/audience: stand-alone application, web-page, portable, scientific analysis, flash-game, professionals/children, ...
Reduce the learning curve of a new user.
Rather than disabling or hiding options, consider giving a helpful message where the user can have alternatives, but only where those alternatives exist. If no alternatives are available, its better to disable the option - which visually then states that the option is not available - do not hide the unavailable options, rather explain in a mouse-over popup why it is disabled.
Stay consistent and conform to practices, and placement of controls, as is implemented in widely-used successful applications.
Lead the expectations of the user and let your program behave according to those expectations.
Stick to the vocabulary and knowledge of the user and do not use programmer/implementation terminology.
Follow basic design principles: contrast (obviousness), repetition (consistency), alignment (appearance), and proximity (grouping).
(See answer by paiNie) "Try to use verbs in your dialog boxes."
Allow/implement undo and redo.
Windows Vista User Experience Guidelines [http://msdn.microsoft.com/en-us/library/aa511258.aspx]
Dutch websites - "Drempelvrij" guidelines [http://www.drempelvrij.nl/richtlijnen]
Web Content Accessibility Guidelines (WCAG 1.0) [http://www.w3.org/TR/WCAG10/]
Don't make me Think [http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/0321344758/ref=pdbbssr_1?ie=UTF8&s=books&qid=1221726383&sr=8-1]
Be powerful and simple [http://msdn.microsoft.com/en-us/library/aa511332.aspx]
Gestalt design laws [http://www.squidoo.com/gestaltlaws]