If you are designing or redesigning your website now, you should look at some of the current design trends.
Responsive and flat design have both been trendy in the past year, but plenty of older sites have never upgraded. If these terms are unknown to you, that might be a reason to hire a designer! But put simply, flat design is a style with minimum use of elements meant to give the illusion of three dimensions. That means not using drop shadows, gradients or textures, and employing simple typography and flat colors. Designers like flat design because it allows interface designs to be more streamlined and efficient. The current version of the CondeNast.com site is a nice example of flat design. (More on responsive design)
Lack of updating is also a cause for not having a real mobile alternative for your site. That doesn’t mean just that your site can be viewed on a mobile device – any site can be viewed, but does it work efficiently on that platform? This requires a completely different view of the site.
This graphic from Coastal Creative shows 8 trends they expect to influence designs this year. Not every one works for your site. For example, the “cards” design is very popular, but it’s not for all applications.
Source: 8 Design Trends You Can Expect to See in 2016 | Red Website Design Blog