Ok, I've been a leecher for a looong time, so now I want to contribute.
Here are my gold making tips. All of them are from a Latvian Trinity WoW server. I know, that many know them alredy, but for those who don't:
1)This one requires Tailoring(30)
You just buy Linen Cloth - Item - World of Warcraft , Make it into Bolt of Linen Cloth - Item - World of Warcraft , and then into Brown Linen Pants - Item - World of Warcraft .
As Linen Cloth - Item - World of Warcraft on my server sells as low as 50s per stack and Brown Linen Pants - Item - World of Warcraft sells for about 3G a piece, you can easily see the profit. 3G-2c(Coarse thread)-10s(4 Linen Cloth - Item - World of Warcraft profit (Excluding AH posting if unsuccesful)
Basically you can do this for any type of cloth, as long as it sells cheap. People buy those items, so they can disenchant them and Ench mats are usually more expensive than the mats for green tailoring items.
2)This one requires to go to Stormspire in Netherstorm, Outland. There is a pet vendor Dealer Rashaad - NPC - World of Warcraft . He sells few non-combat pets. As two of them (Blue Dragonhawk Hatchling - Item - World of Warcraft and Mana Wyrmling - Item - World of Warcraft ) look very good, you can buy them from the vendor and AH them for about 2x buy price. Many players don't know where to get them and will just buy them from AH. Also in Stormspire is a vendor Dealer Senzik - NPC - World of Warcraft . He sells many green Outland gems for 1-2G in limited supply(1). You can buy them and resell on AH for about 3x price you bought them.
You shouldn't flood the market with pets. I usually have 1 of each auctioned at all times.
3)This one (to be effective) requires WoW Emu Hacker and at least level 65. It's doable on lower lvl, but it's hard. You can get the Emu Hacker on Deathsoft.com. It requires forum registration. Among features of this Multi cheat there is Teleport. I have attached my teleport list to this post.
Ok, In Dire Maul Arena every server restart (On trinitycore as far as I know, although it should spawn every 6 Hours 20 minutes) spawns one of these elites Skarr the Unbreakable - NPC - World of Warcraft , Mushgog - NPC - World of Warcraft , The Razza - NPC - World of Warcraft . They all drop 2-4 World drop BoE blue pre-BC items. You can sell them for nice prices on the AH for the disenchanters. The item I'm farming is the famous Orb of Deception - Item - World of Warcraft . It has a 13% chance to drop from Skarr, and 4% to drop from both other spawns. So I usually log in, and use WeH to teleport to the arena and kill the spawn. For a 70lvl mage, it's easy. So far I have got 2 Orbs. When I get one I do not put it on AH, because there isn't enough intrest. Instead i post it in the Global chat for 1k gold. And both of them sold in 20 minutes. Time invested - 10 minutes every logon, profit 1000G.
I hope something of this was new for you. Using only these 3 tips i quickly got 5000g for my epic flying training.