Elevator pitches are useful ways to set out your case for funding. They provide not only a short introduction to your organisation work but also a basis upon which a longer letter can be built. I often use the Starwars story as a way to illustrate this. A useful exercise it to write a line or two for each heading which can then form your pitch.
Set the context (the Galaxy / Empire and Rebellion)
This should set the scene of your work; where you work, who with, and the problems those you work with face
Introduce the Hero (Luke Skywalker)
This is you; what does your charity do; how does it make a difference to the lives of people. It is important it is not just what you but the difference you make, and what makes you different to other organisations.
Describe the problem(s) that you face in delivering your work and supporting people; what is the impact of the problem. Try and make this specific and easy to understand.
This is the solution you have identified to the problem; why do you think this will work, what will be the benefits of the results
The Resolution (Learn the ways of the force)
This is really the ask; what can be done to help you deliver your solution to the problem. What do you need the reader to do; be direct; if it is money ask for an amount, if it is volunteers say what tasks are needed…