No calls to action
Have you made sure to include clear calls to action on relevant pages? Do users have an easy means of contacting you? If not, do not feel too bad – this is a mistake I have seen made by many. At the same time, it can be a crippling mistake if your aim is to bring in new leads from your site (which, presumably, it is).
You need to think extensively about the sort of action you want a visitor on your site to take. Do you want them to subscribe to a newsletter? Submit a membership form? Purchase a product? Share your content?
Your answers to those questions should inform the design of your site – websites are always best when they are created with their specific audience – and a specific action – in mind.