OK. Going by what you said, the best way is to actually build something that works, and if possible non trivial (you can even try to clone an existing popular app as you can focus on actually implementing it than brainstorming ideas), and showing it at places like HN, CodeProject etc with your profile clearly mentioning you are looking for a job (and a career change). Action beats words. If the app you have already built is in good enough working condition, you could use that itself. Being in between jobs is even better for this adventure as you can dedicate full time to this with no distraction. Good luck.
I am in a similar boat as you, except I am trying to move from C++ desktop to web domain, and this is what I am doing - building apps (actually porting my private desktop apps to web platform). Once I am happy with the quality, I will leverage on them. Of course, I am looking for a position comparable to my current one (lead dev or more) so I am being a bit more thorough etc.
> I was starting to once again decide if I wanted to found something or look for a job, then I realized I actually wanted to be a developer. So it is a mature decision.
You mean you want to work as an employee for someone as a developer and not be a developer entrepreneur? Just want to know.