I make about 5-6g per day with tailoring on my lvl 14 priest.
It takes me about 10-15 minutes.
I could probably make more, but im lazy and have been playing my paladin almost exclusively.
Heres how you make a bit of money with tailoring:
1. Buy the mats cheap on AH.
You should be able to get linen for around 20-25s per stack of 20.
Wool for 30-40s.
If you get mats while doing your quests... Great, more profit for you :)
2. Mark it up a huge amount.
Green(uncommon) items should sell for a minimum of 15-20s. Anything with +int will sell for more.
Anything that requires a pattern will also sell for more.
Prices will ultimately depend on your server.
3. Only make 1-2 of each item you are going to sell at a time, but make a ton of different items.
This is the most important step, and the part where most of the non gathering professions get themselves in trouble.
You cant ever have too many copper bars or herbs on AH since they dont cost you anything other than time to get, but if you flood the market with 20 brown linen robes you wont make any money.
If you instead put up 2 each of every green(uncommon) robe you can make, odds are you will sell them.
If they dont sell, then your only out the cost for 1 or 2 items, instead of 20 ;)
4. Repeat. Over and over again.
Consistancy is key.
BTW, I have over 30g on my priest(tailoring/enchanting), which is way more than I need at lvl 14.
Hope that helps...