I expect I've blogged about this before, but the question came up on one of the lists recently so I thought I share how I transfer the bouts from the back beam to behind the heddles ready for threading.
Here is the beam all ready to go - 30 sections.
Each bout is taped to a long stick. Once all the sections are taped to the stick it is then 'threaded' through the beams. This is why I have plastic covering the lower beam. If it isn't covered the warp threads can catch on the sectional dividers on the lower beam and get pulled off the stick.
This method won't necessarily work for everyone. I don't make a cross, just peel the tape back and pull the threads from the tape for threading. If you make a cross, you will probably insert the lease sticks into the cross and suspend the sticks from the castle.