I invented this tool a while ago to give my brain some fun activity while doing daily chores like brushing my teeth. The concept is as simple as effective:
This excellent exercise which I got from Barbara Sher will help you to make a starting point for your project. It can also serve as a tool for self-coaching when you are stuck.
Make a brainstorming with yourself (for rules of brainstorming, see here).
First of all, define a starting question, f.ex. "How can I start my online business?". Then, assume different characters and give yourself suggestions and ideas which can help you with your question. For some unconventional results, Barbara Sher suggests far-out characters like: