Your goal as the writer of a proposal is to get your paper or project accepted out of several hundred or several thousand entries. Typically, proposals are reviewed by a group of people related to the conference. These people are forced to review all of the proposals sent to them. They are overworked and tired and you have to catch their attention. Read and reread the directions.
All conferences have different requirements for proposals.
Make a checklist of all of the instructions to compare your final submission against. Try to find copies of successful proposals from past meetings of the conference you are interested in. These examples would be invaluable in helping you develop your winning proposal. You may also be able to find past programs that would list topics discussed and presenters names. You may be able to find a professor on your campus who has presented at that conference before.