Take a blank sheet of scrap paper and begin making an outline for your art project. While this will not actually be a part of the proposal, it is extremely important to get your ideas on paper before attempting to conceptualize them within the proposal. Depending upon how you like to work, there are a variety of different ways to outline your project. Many people simply like to brainstorm on paper, while others prefer to work with a structured plan with a variety of stages and steps. The important thing is to be able to transfer your mental ideas to paper.
Begin writing your proposal. You'll want to structure your proposal much like any other thesis proposal, beginning with an introduction followed by a thesis statement, and next outlining your approach and the methods you intend to use. Elaborate on the implications of your project and what you intend to achieve. Finally, provide a timetable for how long it will take you to complete the project. It also helps to include a title page with an abstract that summarizes the project in approximately one to two paragraphs.
Proofread your proposal. Ensure that you mull over each page of the proposal at least a few times to weed out any potential grammatical errors. While proofreading on your own is important, it can be immensely helpful to have another set of eyes take a look at your proposal. Ask family or friends to read it over and to provide you with constructive criticism.