Be sure that the product architecture supports as many of the system's possible directions as you can imagine.

Define the system's core carefully.

Decide whether to lean more toward Evolutionary Prototyping or Staged Delivery, based on the extent to which you need to accommodate customer change requests.

Order the functionality in your initial set of releases from "most certain" to "least certain." Assume that the number of changes will increase in later releases.

Explicitly manage user expectations having to do with schedule, budget, and performance.

Consider whether pure Staged Delivery or pure Evolutionary Prototyping might be a better fit for your project.