The short front posts are simple, as they are short and straight. The back, main posts, though, are usually curved so that you don't have to sit bolt upright. It's best to use a small bent tree that can be split into two equally curved pieces. An alternative is to bend straight green pieces by tying the ends together with a block in the middle to get an equal bend on them both. The problem with this method is getting back posts dry enough to hold the bend, yet green enough to season shut around the rung tenons. Usually, it works out all right, but you must remember to balance these two factors.
The posts should be worked to their final shape as soon as possible.
As you did with the rockers, you can clamp the curved back posts together and plane or shave them as one. Most posts are round, so you can proceed to shave them octagonal and then to full round, or you can just leave them square.
A bit of lathe work on the top of the back posts can be added here. This is an easy step if you are using straight stock that you intend to bend. Just put the green stock in the lathe and turn the finials, and then set them up to bend. Even with turned finials on the posts, however, I do all the rounding of the length of the posts with shaves and planes. Few things are as tiresome to me as turning a 4-foot-long cylinder on a foot-operated lathe.
"A Practical Guide to Traditional Woodcraft" By Roy Underhill
© 2012 The University of North Carolina Press