Death is always very tempting for a straight forward, burst mage play, especially if you rush it. You can farm like a beast very early on thanks to it. But, if you play him more to be a bully during the laning phase, you'll want to torment your opponent with Q's. If you're upping your Q first, though, the extra fire damage from the augment isn't as helpful early game, so holding off on your augment and instead building your Rabba's first or a Haunting Guise is an option.
Couple options for other augment use, though: getting blue gives you a good initiate, especially if your mid opponent is being a long range machine. The W range essentially turns him into an anti-poke. I've used it for support Viktor as well, but the problem is that by late-game you just don't contribute enough. The W works better if the rest of your build is good damage.
Then there's the yellow augment...oh lord, is that thing underrated. If your team goes for a "everyone play tanky" strat, building him around this (with a Rylai's and a Liandry's) is pure joy. Poke comps...not only can you do the general Viktor poke with your E, but you can land a Q and get out of there. As Phreak noted, playing as a bruiser top. It's not guaranteed to work, but I turned an enemy Darius into a miserable man by just poking constantly with the speed boosted Q and using that speed to get out of his range when he lands his E or just avoid the E all together.
Also, sort of side note to the question: Q augment is the best on Dominion. I know most of this is applying to SR, but just figured I'd mention it.
And finally, people need to stop saying that he should be able to buy all the powers. That's not the point. The point is that each one should change how he is played in general. The revised augment system is most likely going to base itself around this by letting you augment whichever Hexcore you got first into something even better and more in line with that role (ex: the tank/sustain yellow augment, when one of the prototypes for the new system was leaked, made it so that his ult healed him and did more damage on the D.O.T part when upgraded a second time. On the other hand, the 2nd upgrade to the Red Augment gave his ult more damage on the burst, but not on the sustained part).