First you need to select the right investor. You should check if he is specialized in investing in the right categories you need him for. If you want to pitch him for electronics, you need to select someone who is interested in this field. Second, to facilitate the introduction you need to make it simple. Introduce yourself and what you have done. You could send him your about me on your profile, or your bio, or a project you have made before. If you have a detailed business plan you could send that to. But before the business plan, try to make a brief, simple introduction of yourself and then ask if he is interested in investing whatever project that you have. Give him a very brief idea of the project. If he is eager to get more information, he will ask you.