One fun practice exercise is to take a real-life object--in this case something mechanical--and try to make it into something way different.
In this case, I was inspired by all the goddamn road construction around my workplace. Amongst all the heavy machinery, there were also several pieces of surveying equipment on tripods in and around the area, and I thought that, with their lenses, they looked vaguely robotic. Soooo... naturally I decided to try and invent a robot based off a piece of said equipment.
I Googled some images of surveying tools, and found one that I thought looked properly robotic. Then, I tweaked it a bit in this quick sketch, changed the colors around, and then added a "body" and some legs. As it is just a quick sketch, it is of course fairly quick and loose, and definitely not very detailed.