A consulting proposal is a document that outlines the nature, scope, and timeline of a specific consulting project. A consulting proposal is a document that outlines everything that you, as a consultant, would deliver for a potential project or client.Learn how to write a consulting proposal for maximum impact with top tips from Melisa Liberman. Download consulting proposal templates for marketing, business, IT, and human resources. Includes real-world examples. The submission is to be clearly marked. (indicating the category of the professional service) – "Sealed Submission Enclosed" (e.g. A consulting proposal is a document a consultant writes to a potential client regarding working together on a project. In this guide, we'll deliver design tips and unique consulting proposal templates so you can get started on building winning proposals right away.