Getting an Idea to Market - Your Stories

I’ve been particularly interested of late about getting some ideas I have had knocking around into some kind of order and seeing if I can push them myself to get them to market. With the market now a big sluggish I’ve got a bit of spare time on my hands these days.

Has anyone here got any stories about bringing their own ideas to life, manufactured them themselves or sold the idea to a company from which you then gained royalties ?