If the classic end is a bit like vanilla (which seems to be enough), here are some ideas for you:
-You need at least one agricultural specialty. In vanilla, you can’t use tracking herbs and tracking ore at the same time, so you have to choose one (if you want to find the second, do Skinning). Selling these is quite profitable, but it takes a lot of patience.
-to be frank? If you can avoid flat-level first aid, you can also sell that cloth.
-The same goes for cooking. Fishing, put all the fish there, plus the drops of useful meat (etc.) you get in cooking, and then sell them all. [Reminder-fishing with vanilla is no different than now. You ca n’t catch things all the time. Even in the swimming pool, increasing your skill level will reduce your skill level.
-Resale from AH. I have a slow, but still profitable trade that continues by reselling low-priced AH projects. Occasionally, the market goes down (usually because those idiots underestimate the price of their goods) and you can buy things that usually sell more. I do well with the biggest slot bags and usually make a profit of 1-2 wow gold classic for resale. This is a slow process, but keep in mind that the amount of gold in the game at that time was trivial, and 1-2gold / bag was actually an important step towards your mount.
My number one bestseller, and to this day (almost 15 years later) I am still very proud:
I bought cheap iron bars (or the ore I smelted into iron bars-in fact the ore is usually cheaper), bought some coal from NPC suppliers, and then smelted it into steel bars. 30 silver iron/coal can be sold for 1-2gold per bar. I really don’t know why I am the only one (on my server) who notices this, but this is incredibly effective. It pays for the mounting / training costs of several characters. You’re welcome.
[Another (scum) "trick" that you can do is post many individual materials with mismatched prices. One feature in AH is that they are removed around TBC, where you cannot always sort correctly by unit price. The result is, for example, if you auction 10 rebars as 10 separate 1 rebars, you can (for example) set their prices at 1g, 1g, 1g, 6g, 1g, 6g, 1g, 6g, 1g, 1g, 1g, 1g, 1g. If someone wants to buy a bunch of reinforcing bars, they will click each one in turn, and may not realize that the price of one pair of reinforcing bars is 6 times before buying. This is a low-rent house trick that won’t let you make any friends. I found out that it was because I accidentally have mistaken the price and got a very angry note from the buyer, accusing me of doing so on purpose. But it works, so I put it here. ]