Human Factors International published a post outlining some important usability principles folks should practice when building an app, a website or a product. Here are ZURB's tips and examples around these principles.

The goal of your site or app is to meet specific user needs and marry them with your business goals. Using motivators helps draw different types of users into specific parts of your site. Understanding the triggers that prompt people to take an action is the key step before you can add these motivators to your site or app.

HFI uses out some good questions to define this one: Who are your users? What are their tasks and online environment? The page flow of your site must match the user workflow.

The ability to find something a user is looking for is 80% of usability. You've got to nail the navigation structure and search. As HFI points out: if they can't find it in 3 clicks, they're gone.

Make your controls understandable. Think through where you want people to click and when. Avoid confusion between emblems, banners, and buttons.

Not only does Google punish you for slow load times but your website visitors tend to leave your site if they are "on hold" for a long time.

Test early in design using low-fidelity prototypes. Don't wait until the end, when it's too late.