Having a great user interface can be the difference between having a successful product and having a product that fails.

When looking to create a user interface, you want to be sure that the interface is easy to use and also engages the user/customer and directs them to any action that you have defined. Users want to be able to easily navigate through your website or mobile app and find the information they are looking for quickly and with little hassle. With websites and web applications, If a user visits your site, and they have to click around for an extended period of time to find the simplest of details, a vast majority will become frustrated and lose interest in the site and your message. This can lead to lost sales, lost customers, and lost revenue (which no business owner wants).

Some key points to think about while designing your user interface, whether it be for a website, a mobile application, or a software application are:

1. Is it Clear?
   This is one of the most important things to consider. Can users easily navigate through the application? Keep in mind, you are not there to show them where everything is or how it works. Users need to be able to easily figure that out on their own.
2. Is it Concise?
   Keep things clear, but also keep them concise. If something can be explained in one sentence versus ten, go with one sentence. People in general are busy and do not want to read a book when they can get the cliff notes version instead.
3. Is it Familiar? Is it intuitive?
   Again this goes along with the user being able to instinctively know how to navigate through the site/application.
4. Is it Responsive?
   Let’s face it, most people do their internet browsing on a mobile device while on the go. So be sure that your application/site looks good and scales to any screen size.
5. Is it Consistent?
   Human beings tend to develop habits or patterns. Users will see consistent colors for example and relate specific functionality to it.
6. How Does it Look? Is it Attractive?
   Although this may be/seem a little less important, nobody wants to look at something that lacks any visual appeal. (I would definitely spend more time looking at and admiring a rainbow then I would a gray, overcast sky.)
7. How Efficient?
   How much effort does it take to get from point A to B within the application? Chances are if I have to click 10 times just to see the hours of operation, it’s not efficient. Again, people are busy and the more efficient it can be with the least amount of effort, the better.
8. How Forgiving?
   We are all human and none of us is perfect (at least I know I am certainly not). People make mistakes. How does your application handle those human errors? Are errors easily able to be corrected or will those errors have costly consequences? Keep the human in mind when mistakes are made and guide them to a solution, don’t just yell at them!

When considering your next UI upgrade, keep these key points in mind and you can have a user interface that is both good for business and a success with users.

You can see more details here:

https://www.safaribooksonline.com/library/view/the-essential-guide/9780470053423/00_cover.html