The world of donations is a grand one filled with opportunities for many causes. The first step in seeking out any donation assistance to a company, individual, or organization is to define your cause. Why are the funds being sought? What will make a company or individual want to donate to this cause? Both questions are important in creating the desire to donate.
Consider the audience of which you are writing to in order to understand how to frame the letter. Your audience must know how to relate to the cause. Additionally, that audience must feel prompted to action - which is to donate. Some research may be needed to further understand this group of whom you are looking to for monetary support. What makes this group interested in this particular cause? How are they connected to this cause and why?