When you design or redesign your website, don't overlook the basics. Educate yourself, and ask all the questions you're entitled to.
To get you started, here's a checklist of common website mistakes:
1. Your site doesn't look right on phones.
Mobile now accounts for 12% of global Internet traffic, and it's scaling faster than the desktop did. If your website is not mobile enabled, you're going to miss out on a growing population of users. You can perform a simple test of your website's mobile friendliness at Google's GoMo site.
2. It has too much flash.
Flash is really cool for visuals, but it doesn't work well with search or Apple devices. So if you're the kind of business that relies on search to be found, or if iPhone and iPad hipsters are your target audience, don't be MIA with a flash-heavy website.
3. You've overoptimized it for search.
It may be a natural impulse to load up your website with keywords and keyword hyperlinks, but what you'll probably create is an SEO nightmare. If it looks like overkill to you, it's probably overkill to a search-engine spider, too.
4. Your content is boring.
You don't want too much flat, dull, uninformative text. Try to include a lot of images, graphs, videos, polls, downloads, or other forms of interactivity so your visitors have a reason to stick around. Here are some ideas.
5. You forgot a 'call to action.'
If you're paying someone to market your website and attract visitors, be sure to ask those visitors to do the thing you want them to do. I'm talking about: "Call now," "Request a quote," or "Complete this survey."
6. You left off or buried your contact information.
How many times do you visit a website and want to call the company, only to find the only option you have is to complete a form? Do you become suspicious of the company's legitimacy or interest in helping you? Make all contact information--including social-media icons--readily and repeatedly accessible. I recommend putting these details "above the fold" and present on every page of your site.
These days, if you're not pulling in some aspect of social media--Facebook updates, Twitter feeds, YouTube videos--into your website or giving users an easy option to disseminate your content onto these networks, you'll look as if you're living in the Dark Ages.
8. You didn't register in local search directories.
If you do the majority of your business locally and you're not taking advantage of freelistings in important go-to local resource directories such as Google+ Local, Yahoo Local, Yelp, or others, you'll have to pay for better visibility through advertising.