How To Become A Business Proposal Writer . The proposal audience is the most crucial factor to get right when preparing the proposal. [4] have another set of eyes (or two) read over your work. How to Write a Business Proposal in 6 Steps from fitsmallbusiness.com Winning proposals requires those facts and descriptions to matter to the evaluator in a way that impacts their decision. Introduce your company to your buyer. Proposal writers typically perform the following tasks in their roles: