Aquaculture extension specialists strive to be useful for their stakeholders. They also try to identify and develop new tools to help ensure aquaculture businesses are profitable and succeed. Often, we need to rely on others to help develop these tools. This presentation will discuss questions to consider when developing a new tool, handling unanticipated setbacks, and finalizing a tool. A case study for the evolution of the University of Maryland Online Economic Spreadsheet Tool for Oyster Aquaculture (Figure 1) based on stakeholder needs and inputs will be presented so you can learn from my mistakes.