User will generally avoid elements that are unclear or not presented in a simplified way. They avoid the design that left them wondering what to do next.
b) GUIDE THEM TO THE NEXT ACTION
User generally prefers doing something if he is asked to do so. We cannot expect user to do something on their own, create call-to-action banners instead. It helps a lot.
c) KEEP IT SIMPLE
The best interfaces does not have unnecessary elements. When you design just ask the question to yourself that does it really needs all these elements ??
d) VISUAL HIERARCHY
A clear visual hierarchy helps user to understand the interface and the functionality. Design the interface in such a way that helps user to focus on important things. As a designer should have the ability to communicate elements better with the help of words & graphics.
e) PROVIDE FEEDBACK
User should always be informed about the actions, change of state and errors or exceptions that occur. Always provide user a clear and constant feedback that speak to him. This makes people confident enough to use the product again.
f) TRY MOVING FORWARD
While developing UI's we should iterate a lot. We'll make mistakes, but should always try moving forward :)
UI design is a sensitive task, the points mentioned above will help you do something better.