Just built an octagon pedestal 31 in high by 23 wide.
I used mahogany 1 x 4s, 1 x 3s, 1/2 in birch plywood for panels and 3/4 plywood for base and top.
I cut 16 x 1/4s that were 9.5 in long. Next I cut a 22.5 angle on each end, then used 1 in air nails and glue to make the octagon base and top with these. Make sure length is exact!
I then cut 16 x 1x3 at 29 in long.
These I cut at 22.5 angle lengthwise on one side, then put two together with glue and nailer.
When I had 8 of these completed I used them to connect the base with the top.
Before connecting base, I traced out the 3/4 in plywood on the base octagon, cut it to fit inside, then glued and nailed it in.
After all the stand risers were set, I cut 4.5 in filler pieces to fill the gaps between each riser on bottom and top.
At this point I cut 8 panels of the 1/2 in plywood at 6 x 29in and secured these to the back side of the risers.
I left a 1.5 in space between the top of each riser and top of octagon for the top plywood piece to rest on.
Lastly I filled some wholes, sanded and stained.