Good content:
While this is an offshoot of design, many website design companies do not emphasize on it enough. There are certain website design companies that do both design as well as content writing. Your best bet in terms of ensuring cost effectiveness would be to hire such companies for getting good content. Good quality content never fails to get a customer's attention and can help index and rank your pages higher on search engines.

Browser compatibility:
Many website design companies fail to take this aspect into account when designing sites. Your site may look gorgeous but if it cannot be viewed in any other browser other than the standard IE, then you are losing out on a large customer base. Many people have started using other browsers other than Internet Explorer. Hence, all website design companies need to design their sites keeping compatibility with browsers in mind.

Good usage of graphics:
Today, sites with static text no longer appeal to people. This is why website design companies need to use more graphics and high tech photographs on the sites. Also, sites should never have image heavy pages that take over 10 seconds for loading. Users get easily impatient and will quickly surf to some other site before the page loads! Thus, while it is important for website design companies to incorporate stunning graphics, it should not take too long to load.

Themes and colors:
The colors used on a site need to be in harmony with the theme and business of the company. This is one of the most important aspects that all website design companies should know about. Every company has its own brand identity, which needs to be preserved while designing a site. Right from colors used to logo design, all aspects need to be in adherence to the brand essence. Always look for website design companies that preserve your brand image in the design.

Navigability:
Nothing turns off customers more than bad site navigation. Hence, while designing a site, website design companies need to ensure proper navigational elements. The search functionality should be robus and users should find things easily on the site.