A used CD mounted to a dowel with a hook on top works very well. It's a great weight overall and spins extremely well. You can screw in a small hook on top, or carve a notch into the dowel. Dowel should be about pencil thickness, and at least 12". The trickiest thing is mounting the CD to the dowel. I did it once with tape around one small section of the dowel to thicken it to the CD hole's size, and just wedged the CD onto it. It was functional but a bit clumsy; there's no doubt more elegant solutions. But that's one way! CD spindles weren't my idea, others have used and loved them. They do spin quite well, better than many store-bought ones. And their light weight will make it easier to learn on. I mounted my CD on the top, top-whorl style, but you could do it bottom-whorl if you preferred. I've only used top-whorl spindles, so I'm partial.
I've also made some from craft-store wheels slipped onto dowels. Those are nice in that they already have the perfect hole size drilled out to fit a standard dowel.