Enchanting, or more exact disenchanting, can make a lot of money. But not very much alone. If you combine it with Leather working however it can be a great way of earning a lot of money. There are especially a few combos that are good. One of the best is Nightscape headband, lw skill 205

It is made from 5 Thick leather & 2 Silken Thread. Quiet normal price for 20 thick leather 1 g on ah, although its not hard to get it cheaper. 2 silken thread cost 10 s. For 20 thick leather & 8 silken thread you pay in total (1 g + 4*0.10=) 1.40 g. From that you can make four Nightscape headband which can be sold to vendor for (45*4=) 1.80 g. Okay here is a small profit, and it will of course rise or fall depending on leather price. But if you instead disenchant these you will get roughly (values taken from a disenchant addon I use):

79 % 3,5 vision dust
17 % 1.5 greater nether essence
4 % 1 Small radiant shard

20 vision dust is roughly priced 10 g buyout at ah
10 lesser nether essence is roughly priced 12 g buyout at ah (lesser is more expensive than greater :-)
1 Small radiant shard is roughly priced 1.25 g buyout at ah
(Values taken from auctioneer addon i used for 1.5 year)
3,5 vision dust = (10g/20*3.5) 1.75 g
4 lesser nether essence = (12g/10*4) 4.8 g
1 Small radiant shard = 1.25 g

Now taking chance of each result into account

79 % 3,5 vision dust 1.75
17 % 1.5 greater nether essence 4.8
4 % 1 Small radiant shard 1.25

Ordinary disenchant value ((0.79*1.75)+(0.17*48)+(0.04*1.25))=2.25 g

In my example I made four Nightscape headband for 1.4 g and if i disenchanted these will they according to my formula be worth 2.25 each which means (4*2.25) 9 g. Total profit will be (9-1.4) 7.6 g.

I have counted with buyouts here so the profit will obviously go down if you cant sell you disenchanted stuffs for buyout. But even if you only can sell it for half the price you will get a nice profit (9/2-1.4) 3.1 g.

Adding time to the formula it takes 30 sec to make one Nightscape headband. 2 minutes to make 4. Add to that 30 sec to disenchant them and another minute to bid for leather and putting up the disenchanted material them up on ah. That will make 3.5 minutes. At buyout profit that means (60/3.5*7.6) 130 g earned each hour. At small profit, each enchanting price halved, that means (60/3.5*3.1) 53g/h.

So over 100 g/hour without ever leaving the city and without cheating or scamming others. Sounds god doesn't it. The obvious limitations is ofc the thick leather supply (and ah-price) and the price on your server on vision dust and nether essence. The other limitation is that you cant really flood the market with your dusts and essence.