re: Getting Bent

The wood gets compressed on the inside radius and stretched on the outside radius.  In my (limited) experience, the wood usually breaks where the grain runs into the side, which is why straight grain that runs end to end, at least where the tightest part of the bend will be, is so important.  Using green wood should help as well.    

To help prevent breakage, I usually use a bending strap (aka strap clamp).  You can buy one at Lee Valley but I made my own from some flashing for a couple of bucks.  I cut a strip of the flashing about 2" wide and attached a small wood block to one end with a couple of screws.  I lay the piece I am going to bend against the block and attach another block to the strip against the other end.  After steaming the wood, I put the piece between the blocks and start the bend.   The strap goes on the outside radius.  I usually clamp in the middle of the bend first and work around in both directions but for relatively short bend on a cane, I would probably start with the end and use the leverage of the cane body to give me leverage to make the bend in one motion and then clamp in place.   I have successfully bent wood without the strap when there is no diagonal grain but using the strap has made the failures less frequent.    I don't know how difficult it would be to use a strap with a cane but if you can get green branches which naturally have no grain exiting the sides, it may not be necessary.  If you end up having to just buy some lumber and cut your piece from that, the strap should help a lot.  

Just thinking out loud but with green wood, you may have to wait longer for the wood to dry and set.  It might not hurt to use a heat gun or blow dryer.    Heat will help lock the lignin and reduce the spring back, while also speeding up the dry time.  Also, I mentioned over bending a little to help with spring back but I would also leave a little extra length so that you can trim the handle end when the bending is done.