You need to pimp your stuff on forums, FB groups etc.
Most of my stuff is for RC tanks so I post a lot on RC tank forums, showing off the stuff I've made. I also keep a
Blog of the things I'm building and my
Blog address is always in my forum signature. Same with FB and Google+
I make videos of my tanks that I put up on
Youtube. They link to my
Blog which in turn links to my
SW shop.
You need to get on as many groups etc as you can and let people know your making stuff and get them interested.
See what I did there?