QS is not the way to level your crafters. In fact, I believe it is the least efficient method to do so and is pretty much the equivalent of a combat class leveling up by beating up countless weaker mobs. There is a good reason why we are required to actually craft an item before we can QS it.

The fastest way to level your crafters without resorting to leves and beast tribes is to actually craft items in your level range and attempt to HQ them from NQ mats; do your daily GC turn-in(s); and complete your challenge logs. After you have exhausted your quick exp methods for the day/week it's on to collectibles.

Of course, I am not saying you can't level through QS. You're just going to burn through far more shards/crystals, gil, and mats doing so opposed to leveling up through more traditional means. If you are going to do it this way, you simply choose the highest level item you can QS with the most convenient to obtain mats and go to town. No other way around it really.