One thing that can be considered very difficult to do is to convince people. Convincing people has something to do with making a proposal and make them agree with it.
In writing a proposal letter, it is very important that you consider so many things about the person you are writing to – their time and availability, line of work, personal preferences and among others.
You need to keep your proposal as short and direct as possible. It is not an expository or composition writing where you can put anything that comes to mind. In a proposal letter, it has to be concise yet full of the information that the person needs to know about the proposal. You do not have to include all the details of the proposal in the letter as attachments can be made with the letter. All you have to include is the general idea of the proposal, its aims and goals. You also have to make it seem like it would be a great waste if the person decides to reject and say NO to your proposal. You have to sell it out to the best of your ability.