I thought it might be of some interest to describe my typical workflow from idea to reality. So let's give it a go!
First thing is the idea or concept. Where the ideas come from is hard to pin down. This idea came from a trip to Alaska my wife and I took in the summer of 2014. Somewhere along the trip we were talking to a tour guide or local about the possibility of renting bicycles and checking out some trails. With a big grin the person said, "Do you know what we call tourists who rent bikes in Alaska? Meals on Wheels!" This referred to their large and dangerous bear population. I immediately had a picture of a big grizzly bear chasing a bike and its rider down a road, a great automatan. The first thing I do is record the idea before I forget it, it happens, what can I say. I have a Samsung Galaxy 10.1 Note that I have a folder of ideas for projects. The tablet has a stylus and I can draw and write down ideas of what it will look like and possible ways to mechanize it.
I now have nearly all the elements. I have the characters, I know their movements and how they will be powered. All that is left is to design the case to contain all the mechanics.
Once the gear train is working then I turn my attention to the figures. They are cut and shaped a bit and given a trial fit.