One of the most literally overlooked aspects of website design are footers, the area at the very bottom of a page that provides information and links to other areas of the site or outside Web properties (such as social media profiles).
All designers use this space differently. Some of them are information heavy, including "fine print" like terms & conditions or privacy policies. Other footers are used primarily for linking to other sites or pages on the site. Another popular use of footers - and something that is found on most of them - is to provide contact information, which can range from links to social media profiles to an email address and/or phone number to a brick-and-mortar address. Finally, some designers use this area as a call-to-action to entice users to signup for an email newsletter or other promotional endeavor.
How a site owner chooses to use their footer area is largely dependent on the action they want visitors to take, but it's all moot if their footer design doesn't catch the users' attention, and a good design is one that is creative, engaging and in-line with the look and feel of the rest of the website.
For some inspiration, have a look at these 15 fabulous website footers:
Mom & Popcorn
The White House
Me & Oli
The Midnighters Club
Superior Contracting Services