Sand, soak, flatten, paint, trim. Those were the steps I used to make the cane ready for the corset.
The first piece of cane on the left is straight from the roll. The second has been sanded, soaked in a bucket of water, then laid between two towels with pots and pans on top serving as weights to flatten it. The third has two light coats of Liquitex gesso, and the tip of last one has been clipped and sanded to round the end. The cane started like this,
and ended up like this.