With a bit of research you should be able to come across many excellent resources that answer your question.
My personal experience has been: get very knowledgeable about some domain (in my case insurance and superannuation), get involved with many different players by doing grunt work and maintain an interest in all aspects of that domain. Over time you recognize recurring problems and start creating (speculatively) solutions, demonstrate them in the context of solving specific problems for people as you happen to interact with them. When you get a solution - problem match -- SELL!
So far I'm far from being a billionaire, but I do have a nice lifestyle and I'm happy.
