After I had a general idea of the form factor I wanted, I began sourcing parts for the build.
I collected a few parts from bicycles (bearings, quick release for the handle bars), I ordered a hub motor from Golden Motor and scavenged an old scooter from my neighbor for the front wheel and forks. The next step was measuring all these parts and figuring out how I was going to assemble them. When I was sure of my measurements and plans, I welded together the main frame from 1x1 square steel tubing, with a headtube made of black iron pipe. The foot platform is 1/2" birch.
In this photo you can see how I used an adjustable rod to make the height of the handlebars adjustable for different riders.