I did it with void spheres, since it is utter useless for the most part, but other hard to sell items is just as fun.
First, you check the AHprices and the supply of that particular item.
Then you do a /2 WTB 10xVoid Sphere! Paying no more than 60g a piece.
Suddenly you get spammed to pieces by people trying to sell you the sphere. Go back to the auction house and see how many theres leftGreat fun for the whole family.