This is mostly common sense I realize, but I'd like to add a little bit of information on what I've done to make the most out of it.
Basically, the deal is this. Take a stack of Netherweave Cloth (if you don't have tons of it lying around like most people then just buy a stack). Split it up into stacks of 2, or just 1, whatever you feel lucky doing but I use 2 because it visually can look like 20 at first glance.
Here is the strategic way to put your "stacks" on the AH and get people to buy them. Look at the lowest buyout price on the cloth. Generally, there should be several stacks up from the same character or characters with even prices. For example, imagine several stacks are up for a bid price of 2g00s00c and a buyout of 3g00s00c.
Put the "stacks" of 2 up for something like 2g10s00c and a buyout also of 3g.
If you've done tailoring to 375 before, chances are there have been several times you've gone to the AH and bought all the Netherweave you could for under a certain price. This is the person you are "scamming".
How it works: They see stacks up for 2g00s00c and 3g00s00c buyout. They will rush through buying stack after stack, and likely not pay too much attention to it. By setting the bid price higher than someone else, you are putting your stacks of 2 below the the legitimate stacks of 20, and hopefully in the middle of a run of netherweave all priced at a 3g (or whatever) buyout. Making your bid look similar visually will distract the purchaser and make them continue to go about their "Buyout Buyout Buyout Buyout Buyout Buyout...." cycle, and make you turn a 3g stack of Netherweave cloth into a 30g stack.
I know it's not big cheese, but for those of you who are piss-poor in gold and looking for a legitimate non-bannable way to make some extra coin, I've done this several times and have been successful every time.
Note: This could be done with other items that are in high demand on your server. Use judgment and don't expect that you'll be able to make gold per hour doing it, it works best as a daily thing or every few hours; at times there will not be long runs of stacks at the same buyout and it's much less likely to work then.
Bonus scam (didn't check if this has been posted): If you're an engineer who can make mana/healing potion injectors, put them up in singles for 20-30g or whatever full injectors sell for on your server. People think they're getting a steal on an injector that will heal them 20 times, but all they're really doing is getting ripped off and paying way too much for one potion. Do this only when no other injectors are currently on the AH.
Everything posted in here is legit and non-bannable, as every player has the right to put any item on the AH at any price.