I cut a PVC pipe to the same length as my lulav then I stuck my lulav in with the bottom sticking out an inch and taped the the bottom to the pipe, this way the top of the pipe was an inch taller than the lulav which was inside so nothing can hit the top of the lulav, it can't slide up or down cuz it's taped at the bottom and the plastic pipe barely bends so I didn't have worry about that either. I've done this handheld and check-in(once when the TSA guy didn't let me through with it saying its a weapon like item, when I showed him it was just holding a branch he said oh don't worry there'll be plenty of those in LA)