Ultimately, RubyCon, there isn't a lot of RAW guidance, but there are three RAW options, and one post-release suggestion from Evil Hat, with my commentary:
1) A thaumaturgic Contacts roll: GM sets difficulty based on how hard it would be to secure an analogous asset using mundane means, like hiring a mercenary version. Basically when you want your thugs to be supernatural in nature, but still just thugs.
2) plot-device level Contacts roll: the shifts don't matter because the player isn't ever really in control - GM can make it as hard or easy as suits the game. This is for summoning things like the Erlking, Fairy Nobles, Chauncey.
3) the Summoning rules (a three-step ritual: create the containment circle, summon the entity, and then bargain, or defeat it in a psychic contest) can easily be adapted to Construct creation, and Evil Hat would probably suggest that be the starting point right off the bat, in line with their philosophy that we apply existing precedents to analogous situations and not require the wheel to be re-invented each time.
4) Kill something to control it: this contested method was proposed by Fred Hicks as a simplified way to do Summoning/etc., and it is to control enough shifts of power to kill whatever it is you want to create/summon and control. So stat out your desired construct/demon/fairy/etc., then do enough shifts to overcome its Stress Tracks, Consequences, etc. Usually amounts to 30+ shifts.
