Narrow your focus. "Disabilities" is too wide a topic to cover in a paper. Focus your advocacy paper on one disability --- programs for the visually impaired, for instance --- to avoid the mistake of being too general and trying to cover too much territory.
Think about the position you are going to take in your paper. After doing your research, for instance, perhaps you are going to argue that not all visually impaired people want to live in a house in the suburbs and that some would prefer to live in a downtown condominium with neighbors who are also visually impaired.
Work from an outline. Jot down your ideas and then number them in order of importance. You may consider writing about wheelchair users in social events is more of a concern than writing about accessibility in public buildings because this issue is already covered by legislation.
Attend to the details. Use a 12-point academic font, such as Geneva, Bookman or Times. Leave 1-inch margins on all four sides of the paper. Type your name and the title of your paper in the header and set the page numbers to run consecutively.
Start your advocacy paper with a strong thesis statement. Establish clearly your position by writing in the third person. Outline where your advocacy paper --- vehicles for physically challenged individuals, sports for wheelchair users, special kitchen equipment for cooking from a wheelchair --- is going to go in the rest of the introduction. Think of this section as signposts to tell your reader what to expect.
Start a new paragraph every time you change ideas. If you are discussing special classes for the mentally challenged, for instance, and then switch to assisted living concerns, use transitions so that your reader stays with you.
Summarize the content and main points of your advocacy ideas in the concluding paragraph. Remember that no new information can be introduced at this point, so make sure you have addressed all important concerns about training for the visually impaired already. End your paper with a strong sentence that links back to your thesis statement.
Leave the advocacy paper for at least 24 hours. Return to it and check your work for typographical, spelling and grammatical errors. Review your original list to make sure you have included all the points you had wanted to raise. Edit accordingly.