In this article, we discuss how to write a business proposal letter and we offer sample letters and templates you can use as a guide. The proposal should discuss problem statement, objectives, research methodology, research activities, and a time schedule in about 3-5 pages.You want to set up a meeting, preferably with the key decision maker and his or her key influencers, to finalize the solution and start working on the contract. Step 1: Fill out the form. Treat the exercise as one part problem-solution writing, one part argumentative writing, which requires you to anticipate and address possible objections. This guide will cover how to write a cover letter for a rental application and even provide you with a rent letter example to help you get started.