Take your time and establish that you and your potential client share basic business relationship values.
The proposal is the very last thing you do. There are a number of phases you have to work through first.
The story about PLATO is not only interesting, but it will also teach you a lesson or two. It explains the fate of great ideas that are not in sync with the times and how large, well-established companies can make bigger mistakes than they can afford.
The book is a “must read” for all business development, marketing, sales and other revenue generation professionals in the information technology industry.