For incandescent bulbs the electronics is simple; two in series will have the same current but half the voltage, two in parallel will have half the current but the same voltage. And you generally want full voltage (although I once rigged a sign for theatrical use that was wired intentionally to run the bulbs at half the voltage).
There used to be Christmas bulb/cafe bulb strings with really large round bulbs on them. I used those a lot of times. Easy to work with; you drill holes in the back of the sign, then hot-glue from the back. But I think all that incandescent stuff is getting tougher and tougher to find these days. There also used to be these really handy screw-on sockets. The socket had a couple of spikes inside, so all you had to do is lay the zip cord inside and screw it down; that made the connection.
If you end up with individual sockets, one way to keep from going quite to crazy is to prep each socket with short pigtails before installing it. Then you just go along from the back and attach each pigtail to a branch line. Still means a whole lot of wire nuts.
And plenty of chances to do what one idiot helper did on a set of mine; he managed to wire four decorative cove-lighting bulbs in parallel-series-parallel-parallel. So one looked okay (just a little dim), two were orange, and the last looked like it was out (but if you looked closely enough you could just barely see the filament was glowing).
(And if you really want to be confused; on another show I used a bunch of 12v halogens -- the kind you see on high-fashion track lighting -- but I was running them off line voltage. So I wired them in series in sets of ten. That brought down the 120V to roughly 12v per bulb. And that worked great, but one day I was making repairs and I bridged one bulb with my fingers. An incandescent light bulb has a resistance in the handful of ohms. Human body is on the order of megohms. Instead of 12v across each lamp and 12v across my careless fingers, it instantly became .0001 volts across each lamp, and 119.999 volts across me.)
