Start out simply. What sorts of things are you doing in your day job? What technologies do you use in your day-to-day work? At a more conceptual level, what sorts of problems does your work attempt to solve for its customers? From there, ask yourself what other problems could be solved for the customers? Were any potentially profitable ones overlooked? What other existing technologies that you are not presently working with can be used to solve those same problems more cost effectively? Looking at the technology set, what other related problems can you solve that either no business is currently working on or that you could solve cheaper/better/faster, etc?

The intent behind this questioning is the important thing. In an evolutionary context, the work you're doing is like an organism that is adapted to some degree to its business niche. You may be able to strike out on your own by making a business 'better adapted' to the same economic niche through changes in the technology/skills used. Alternately, you may be able to find a niche that better supports the toolkit you presently have to work with. This is the simplest way to generate innovation but it will likely not produce results that are the best for your overall happiness.

For that, you'll have to determine what kind of niche can support you financially and which you personally are well suited for. From there, it's a matter of figuring out what adaptations in your personal skill and technology set are necessary to transition you over to that niche from your existing job.