Occasionally I get asked for some advice about how to be better at design. My advice is simple, do your homework.
Know the history of the problem area
People imagine a lot of design involves a deep understanding of psychology and a mystical expensive process to find great solutions. But even if this were the case you don't want to waste time re-inventing the wheel. At the start you want to know what are the best existing solutions to the problem you are solving. You should have a look at existing solutions, especially those of your competitors. Let say you are working on a payment design and want to have the best possible credit card experience.
Above is the credit card entry page for Amazon.com and Apple.com. Ignoring that the Apple site asks for the security code, can you see another key difference?
The Amazon interface requires the user to first select what type of card is being used. Visa, Master Card or Amex. If you get it wrong the process fails with an invalid card error. The Apple version takes advantage of the fact that each card issuer has their own unique pattern of numbers. It is not necessary to ask the user a question they might get wrong as you can detect the card type from the number they enter. Design genius is not needed here, just doing your homework.
People don't do their homework for a variety of reasons. Laziness and an expectation that being smart will get you through are common. But design projects have a limited amount of time. Don't do your homework and you end up going down the same wrong path everyone else already travelled. If you do your homework you can use the time to work on totally new issues that can make a product better than the competition.
Homework isn't just for the start of a project.
An easy mistake to make is that homework is just for the start of a project. In fact the start can often be a terrible time, as this is when you understand what you are designing the least. As you get a better idea of what the really tough problems are go and look again at how other products tackle the same issue. I often find many things I missed the first time and also have a greater appreciation of why certain products work the way they do.
Make sure doing your homework is part of the process
An easy way to ensure you do your homework is to make it part of the design process. Make sure you are constantly up to date on how your competitors products work as well as any other relevant design solutions. As most people don't do their homework it gives you a surprisingly large advantage from a small amount of effort.
Don't believe me? Here is a screenshot from todays iOS 8.1. Look carefully. Can you see where someone at Apple is not doing their homework?