I had huge trouble both with base and the stem. The bottom faces of the stem “holder” seemed to first point downwards and then merge with something else.
On my third try with the base I got it right but I forgot to create the “sheath”. When the base was done, I was happy with it and decided to just select the edge loop, extrude downwards by 0.2 and then fil the bottom with a new face. I’m hoping that we are employing the newly learned techniques to memorize them, and that my choice to just cut corners like that doesn’t come back to bite me later. But then, if it does, I’ll just make another lamp. And then another. And then another, until I get it right.
…But I do hope it’s good enough now. 
My lamp is also clunkier than most but I wanted to make it as LP as possible to make the render easier on my oldish computer.
