There is no way to sell your ideas, but you can convince people by writing them down.
As for the writing method, you need to have a mechanism to analyze things easily. Start your writing with the introduction, where you explain the idea in general, followed by the details of the service or product. For example, if it is a beauty company that has shampoo, even if there are 10 different types, you don’t have to explain them fully.
After doing long research, you should write in detail the differences between you and the other existing companies and competitors.
Then focus on strengths and weaknesses that can be written either in general or in detail. If the investing is individual, you will need more than the required techniques, personnel, amounts, development methods, timetable, etc.
However, if the investment is a partnership of more than one party, this will be enough.
While if you want an investor with you, you’ll need a torture test and a feasibility study.