Genesis (techfolk)
In the Voidwalkers setting, techfolk start off as software in servers ('creches') until their minds mature enough to be loaded into hardware bodies.
For the TVs, this happens when the scientists monitoring the creches declare that a mind is ready for upload.
For the Soundkind, I'd like to think that as the minds in the creche mature, the scientists hook up some bodies to the servers, and the developing minds get to upload themselves and try the bodies out. They leave the creche when they themselves decide they're ready.
I haven't decided how it works for cams but I want them to 'hatch' from 'eggs' somehow. Maybe they're in walls of pods like in the Matrix (but not gross and slimy) and they climb out when 'ripe'. Maybe instead of servers, cams mature in their eventual bodies. If a mind turns out not to be viable, that body is flushed and a new mind is allowed to develop. But… what if a 'flushed' unit still has traces of its previous failed mind in it? The eventual unit has memories of things that couldn't possibly have happened to it.