put together a very detailed portfolio (like a resume) with details of your experiences, photos of your experiences or of product in action and a broad overview of how you would improve their product or how you could expand their sales with YOUR HELP.
next find out the best person to contact in said company without running off at the mouth to the lower road block employees, (you want to save your energy for the person that counts),
then get yourself some information about marketing (background info on how to market anything, it's all basically the same)
set up an appointment with above HMFIC and spill your guts out, oh and find out as much as you can about the company as you can, stock future, earnings, business mission/vision, and even as much PUBLIC information as you can about the person whom you will be giving your presentation to.
you want to stroke his ego without looking like your trying to stroke his ego.
basically your going to sell yourself and what you can offer the company, what YOU want out of it must remain on the back burner, at least as far as they're concerned.
good luck.