As a business owner, you should be looking for a gap.
The gap that prevents your (prospective) clients to reach the next level in their business.
If you can provide the missing piece, you have a potential business. If you can name the gap, you have a business.
If you have a gap-filler for your clients, it is much (much!) easier to "productize" it with a fixed price, than to re-invent the wheel, and write a proposal every time. That could be a course, a book, or just a defined service.
Ideally, YOU are the only person in the world that can fill this specific gap. Maybe because of your expertise, or your personality.
With a "signature product" it becomes much easier to communicate – because you have a defined goal.
What is your "gap filler"?