This advice, or thought, about how to make more gold in World of Warcraft is related to cloth. Cloth is something that people are always after in WoW for one or another reason. You have the people skilling up tailoring of course, but you also have people who are getting their first aid up. Both leads to cloth always being something in demand. And demand is good for your purse.
The first thing I have to say is something that not everyone agree with. When you are leveling you will come across Linen Cloth, quite a lot of it. My advice is to sell all of this on the auction house right away. And this is the part people might not agree with since you want to level your own first aid or tailoring perhaps. The reason I tell you to sell it though, is so that you get a "pool" of money faster. More money means you can buy and resell more things on the AH and increase the money further. Once you have more money it will not feel like a huge cost to buy the linen cloth you need to skill up your first aid, but the silver you get from selling it early on can greatly help you in your gold making.
The amount of money you get from a stack of linen can vary quite a bit but it´s usually around 10-20s. As you continue to level you will start getting wool cloth. Wool cloth is one of the bigger money makers when it comes to cloth. For some reason it seems to always be a shortage of wool in the world (mages need to make more sheep). A stack of wool cloth can range from about 3-8g on the AH and often it sell even if the price is as high as eight gold. While you are leveling pay attention to where you get a good drop rate of wool as you might want to come back here later to grind some more gold. Wool usually start dropping from humanoids of level 18+.
The wool cloth selling will work well for characters that are not actually leveling on the mobs that drop it, but just want to get some extra gold. Since you will be killing the mobs a lot faster, you will be able to grind a lot more cloth too. Just remember that you do not want to flood the market.
Next cloth worth mentioning is Mageweave, which like wool cloth, seems to be in high demand most of the time with very little of it available on AH. This of course pushes the prices up. Mageweave can sell from anywhere between 3-20g per stack depending on the market. So depending on when you put the cloth on the auction house. If you are able to wait till there are just a few, or no stacks, on the AH you will be able to bring in more gold for your stuff. Which of course is true for anything you sell.
Next comes Runecloth which, apart from the previously mentioned tailoring and first aid, is also used for reputation grinding with the major cities. This of course adds to the demand for runecloth in the game, especially now with achievements. The achievements have worked quite well in favour for gold making in WoW, people now buy a lot of stuff they didn't bother about before. Runecloth is a good source for steady income and it´s also easy to grind, however, the price on runecloth can vary massively.
Netherweave cloth can be mentioned too as it continues to bring in pretty good money even in WotLK. It does work as with runecloth though, the price can vary a lot. Usually a stack sells for between 3 and 4 gold.
Last we have Frostweave cloth. This will bring in good money most of the time since it´s the "current" cloth so to speak. People who are leveling to max out both tailoring and first aid (and are too lazy to grind it themselves) will buy a lot of frostweave cloth. Stacks of frostweave can range anywhere from 5g to 15g most of the time and it might be worth putting out single cloth for a higher price, or at least smaller stacks of perhaps 5 or so.