Definitely take a look at the thread “Failed as an Industrial Designer” in the Design Employment section.
Having done exactly as what you say you’re interested in doing, I would highly recommend NOT branching off on your own directly after school. In my experience, the only reason I’ve been remotely successful at being an entrepreneur is because I had developed my skills, connections and general product development knowledge through years of working for someone else.
There is a big difference between being an entrepreneur that has their own design studio versus one that brings their own product to market. Flat out, I just don’t have the talent to be a design principle but I know I have a lot to offer my clients (I consult on the side.) But what I do have is years of experience designing products right alongside the manufacturing floor. That brings you knowledge that you’d never gain in school. Not even close.
Another advantage to waiting for a while after school to do your own thing is that you learn over the years about the business side of product development. What you bring to the table as an experienced ID’er is the ability to save an upstart company tens, if not hundreds, of thousands of dollars in development, graphics, production assistance, etc. These are all incredibly valuable to a new company set to bring a product to market. And since you work for free as an entrepreneur, it makes the amount of money needed from outside investors less. And less is always good since that means you get to keep more of your company.
Bringing your own product to market also makes you focus on just about everything BUT designing. That’s just a side-show. I’ve continued to provide design consulting to clients because it keeps my skills sharp, even though they aren’t that great to begin with.
So, in a nutshell, I recommend waiting at least 5 years before attempting to bring your own idea to market. You need the industry experience and connections to pull it off. That’s my educated opinion on the matter.