Purpose and Audience
Sometimes it is easier to consider your purpose and audience when trying to develop ideas. The purpose of your paper is the reason you are writing your paper (convince, inform, instruct, analyze, review, etc). The audience of your paper are those who will read what you write. Your audience will not have you there to answer questions about what you write, so understanding your audience's needs previous to writing your paper will let you tailor your writing to that audience.
Start by identifying your purpose, and then write down ideas that fit your purpose. Then make a list of consideration questions you can answer to make a bridge between your purpose and your audience.
Purpose: Convince audience to buy a Dalmatian
Audience: Middle-aged with money and space for a pet
Considerations: What does this audience think about this dog? How can I best connect my argument to this audience's lifestyles? What will be this audience's major concerns about this dog? How can I address those concerns?