After listing five key things to avoid on your website -- particularly when implementing Rich internet applications -- below is a quick list of three absolute to-dos:

Create seamless transitions from RIA to HTML: The transition can be jarring if not executed properly. Remember, users don’t know the difference from a technical standpoint, but they do notice discontinuity. An abrupt downgrade or upgrade in functionality can ruin the experience

Users benefit from staying in context: Users benefit from a simple display of information. It’s important to stay in context and have information update immediately without waiting for the data to go back to the server and having the page re-fresh or re-paint, like in traditional HTML. RIA implementations allow for greater interface design, without compromising clarity.

Give users more control: Visualization tools are a key benefit of deploying RIAs. By creating custom designed products, designers can give users the tools to solve real world problems. A good example of this is Single Screen Checkout, a solution that allows users to input billing and shipping information and then view their orders without having to wait for page refreshes. With more feedback and data readily available, users have more control over their internet experience.