I've searched the forum on this topic and come away with the impression that KiCAD really cannot do panels in any straightforward, professional, and non-error-prone way, so this post is not really to ask for KiCAD workarounds but rather to ask what people actually are doing in order to get boards panelized (or panelised). Here's my history:
In the first batch, I sent gerbers for one individual PCB to Sunstone and told them I needed it panelized so that Screaming Circuits could assemble them. A month or so later my lovely assembled boards came back without further action on my part.
In a subsequent batch, I had the boards made by a Chinese vendor. Again, I sent them the gerbers for the individual PCB and the outside dimensions of the panel that Sunstone had made. The panels came back fine, I sent them off to Screaming for assembly, and again the finished boards came back fine without my having to do anything.
In a still later run I changed to a local assembly house. I gave them the made-in-China panels, and they said "We need gerbers for the panel so we can make the stencil". I was like "What? I have no idea." After a few days, they came back and said "Our stencil vendor has agreed that they can make your stencil" as if this was a major project and inconvenience for them.
Now I have some new small boards that need to be panelized. I sent the gerbers off to the same Chinese vendor with a note that they should make the panels 5 x 8 boards or whatever is most convenient for them, and they came back saying "We can't make your boards without panel drawings".
This is getting tedious, and I hate feeling like I'm not providing adequate documentation to vendors. Any suggestions for recommended practices (apart from going back to Sunstone/Screaming, whose prices are 3x those of China + local assembly)?