The quickest way is to have some body else do it. Namely, the ceiling tile installer. Whether this is done via a bribe of a case of Meister Brau or a subcontract, I am not privy to but whatever he uses, the method would be the same.
The is mention of steel beams. It is not necessary that the steel wires be absolutely vertical. In fact, splaying them out in a V shape up to 45? would actually enhance stability. So use a beam clamp and attach a bunch of your grid wires to that.
Also think outside the carton and consider epoxying a suitable trinket of hardware with a hook or loop on it to the ceiling.
If you can install your luminaires before the ceiling grid is installed, then just use the other guys wires. Paint them yellow or something.
~Peter