I use clear acrylic rod to make a couple of posts. It is sort of the opposite to the ornate brass posts (which I used to use like everyone else). I have gone exclusively to the clear acrylic now. For smaller models one of the plastic suppliers has them in its regular line found on those racks, in 1/4 inch diameter. I also build some larger 1:96 and 1:192 scale. These take larger posts so I occasionally order another half inch "dowel" and keep it in stock. Half inch holds a pretty large, heavy (solid wood) model.
One of my ship models (the whaleback Laker) at http://www.usfamily.net/web/stauffer/shipmod.html shows what this mounting looks like, though I use longer ones on most models. The whaleback just cried out to be a little lower than most.