There really isn't much of a trick to it. You just have to take your time. Aside for drilling the hole for the bead (which I did on my table vise), everything else was done by hand.
I started out using a pipe cutter, but it wasn't staying in the same groove each pass, so I stopped, put a pipe clamp around where I was going to cut it to use the clamp for a guide to keep the saw blade as straight as I could, and got out the trusty hacksaw and finished the cut.
Once cut, I used some 250 grit paper to smooth and face the muzzle and rotated the barrel by hand until smooth.
Once the face was straight and true, I switched to 400 grit to polish and somewhat tapered the inner and outer edge of the barrel by using my thumb and forefinger to hold the sandpaper and turned the barrel back and forth (around) until I got the contour I wanted, then I rubbed some birchwood casey cold blue on the exposed metal.
The reason I cut the barrel twice in the photo above was because of the bead hole. My X/Y vise didn't have as much travel as I needed to go from the factory bead hole to the new bead hole location, so I put the barrel in the vise, moved it as far as I could and drilled another reference hole (inline with the OEM bead), then cut the excess barrel off, and repeated the process the 2nd time to to get the bead where I wanted it while keeping the hole centered in the barrel. It worked out very well.