Your project criteria are a good place to start, but that may still leave you with several ideas or approaches to choose from. You may want to run a focus group or interview users to find out whether one idea is more promising than others. Don't be afraid of risk, especially in this business. It's easy to let risk be the deciding factor. Low risk does not necessarily mean safety, however.
Creativity is an ongoing process, and needs to be fostered along.
High pressure, tight timelines, and failure to communicate with clients can all put this process in jeopardy. Plan for creativity just as you would for other essential tasks, and innovation will not be a lucky event. Instead, it will be your way of working. A survey of creativity theories and practices. She runs Square Circle Solutions, a Boston-based web firm specializing in user experience consulting and idea generation.