A comprehensive and professional project proposal letter template for your career advancement. The format must provide comprehensive information so that consultants can submit a complete and valid proposal. 1.Instantly draft and send a business proposal template to establish the terms and conditions between your business and clients. The letter will state the purpose and value of your project, and what you plan to do to complete your project. Create a professional proposal letter with this free template. Perfect for introducing your business proposal to potential clients. Similarly, the cost of the project is another key item to include in the proposal. Completing the project. 1. Step 2: Purchase Price. This sample letter shows you what to include in a request for an evaluation.