The fantastic thing about web design is that there are so many ways to approach the same problem. You are only limited by your imagination -- and what is possible to do with the code, with visual appeal and with current web standards. Web design companies, talented designers and excellent programmers follow basic design principles to help create a great user experience.
Quality
Without high-quality service or products, you basically have a white elephant on your hand. You know how customers are willing to spend hours in terribly lit thrift stores just so they can store that vintage Prada bag. The same principle applies to web design. Content is everything. Great content -- whether it is a well-written blog, appealing images, a great DIY-type website or products that the customers want and need then customers will end up browsing, ordering, commenting and more.
High quality content and the website's credibility are interrelated. All it takes is one negative review, or one failed delivery and a snarky aside in the comments section to destroy a website. Your company should deliver what the customer expects: great quality quickly and easily. There is no other compromise for this.
Usability
Usability covers two things: how intuitive the site is and how easy it is to navigate. The site should not have to explain itself. Users should instinctively know where to click. The way the site is designed should lead their eyes to where they want to be.
In order to make the site as usable as possible, your web site designer should be aware of what type of customer you target and follow the basic principle for web sites. People do not read. They scan, then read it later if the like what they see. If something catches their eye. This is why most websites have heavy graphics or text on the middle upper right side -- this is the first thing people look at.
Immediate
Anyone who is every routed to a sign-up page when all they want to do is browse knows this: if the form is too long, chances are your customer will close the window. Why? Users are used to getting immediate gratification. They can input an email and password -- please do not ask them for more information unless they are buying something. A website should give the user immediate returns and be fast enough to sustain it. In the time of dial-up, IRC and ancient computers, loading times took as long as 5 minutes. This lack of speed users could deal with, 10 years ago. Nowadays 5 minutes will make you the laughingstock of the Internet.
Simplicity
Great websites take into consideration that the customers do not have time and no matter how web-savvy they are, they also do not have patience. So you and your web development team should make the site as simple to use as possible. This core element affects immediacy and usability, because the simpler the site is to use, the more people will use it.
Keep in mind that simple does not necessarily mean that the website should be plain, or boring. It means keeping all the embellishments down until you nail the user experience down flat. It can also mean complex code behind the scenes to create the illusion of simplicity.
It can also mean scaling back on content and text, especially on the front page. White space and well-written copy give the impression of simplicity and makes it easy for your visitor's brain to process what your site is really about.
Interactivity
Many successful websites share one theme and one core function: they are interactive. They allow the user to shop, click, and play, to learn, to submit their own experiences and to give reviews. It makes your visitor an essential part of the user experience.
Think about it. Some of the most successful websites are actually run by their users: Reddit, Tumblr, Digg, Facebook, and Amazon. Gaming websites that support Massive Multiplayer online games are often full of forums and other member-run areas to give their visitors a chance to form a sense of community. This is something you can aim for as well.
Find ways to include your visitor in the process, by giving them plenty of opportunity to curate on your site. Simply adding a review or comments section can work wonders.
If you create interactivity, remember to follow up on it. Talk to your customers, reply to their comments and emails and help complete their user experience.