Ive made a little gold in the AH on my realm simply buying things in the middle of the week, usually wensday, and selling them on saturday. Its a easy way to make some quick gold. The other trick I use requires you have a rare drop design, like the rituals of the new moon for inscription. You take a few of whatever it is you make bout 3-4 of whatever it is, in my case the Ritual of the New Moon books, and send them to a few different alts. Then once there are none in the AH you list them for 200%-250% of the normal price on all of your alts and then you can spam trade and say your selling for 1/2 the ah price. Alot of people will buy simply to try and resell them and youve just made a bit of money.