Server Maintenance Windows
Keep an eye on the Message Window when you first start up World of Warcraft to see when they reboot. They will usually have a maintenance schedule or give you a couple days notice on when they are rebooting the servers. When this happens there are two things you HAVE to do. Before the reboot, start bidding very low on the auctions that have Short or Medium time left. When the reboot occurs you will be the high bidder and because the servers are offline, other players can‛t outbid you. This allows you to get some very nice items for a lot less than they would normally go for which you can then in turn put back up for sale for EASY money. After the reboot, the Limited Supply Items are back up for sale at a lot of the merchants. If you can get online shortly after the server is back up, make sure you hit up a lot of the merchants and vendors. Some areas that are loaded with them and are very close to each other so you can get to them all very quickly are Ratchet, Booty Bay, and Gadgetzan.
Patch Releases
When a new patch is going to be released, you can usually view the patch notes prior to that. Look for items that are either going to have their stats altered or their % drop decreased. This is your opportunity to start snatching these up like crazy so that when the new patch comes out, you will be on the nice side of the supply and demand allowing you to make a some serious cash. Epics that are involved here will bring you in an INSANE amount of Gold! Also, on the flip side of that, look for items that are going to have their % drop increased. This means the market is about to get flooded with them and if you have been hanging on to them, go ahead and sell them before the new patch comes out.
Transmuting
Certain items in the game are worth significantly more if you simply transmute them before you put them up for sale. An example of this that I use all the time is transmuting Arcane Crystal (12 Gold) into Arcanite Bars -
(18 Gold). If you don't have Enchanting as one of your professions, you should be able to ask a friend or someone in your guild to do this for you. Whenever you visit the auction house, make sure you also look for other items that you can easily transmute for a profit such as Essence of Undeath
which can be turned into Essence of Water. If so snatch them up, transmute them and then put them back up for sale. I have made as much as 100 Gold in a day from doing this.
Parties in Instances
When you join a party or do instance runs, try to avoid groups that have someone of your same class already in the group. This will allow you to get more items that are specific to a class. For example, if there are 2 mages in a group and you are one of them, it‛s going to make it a lot harder to get Rare and Epic cloth items because there are 2 of you fighting for them.
Healing, Tanking & Escorting
Post a message in one of the major cities advertising your healing, tanking, or escorting services. There are a lot of lower level players who would be very willing to pay for your time. If they don't have a lot of gold to pay, you can say that you get to collect certain items along the way or at a specific boss. Whenever you are helping out a lower level player (or group), typically it is an instance or area that you are going to be able to breeze through. This allows you to collect the gold or items that are dropped in a very short amount of time.
Seasonal Items
For whatever the reason may be, seasonal items sell very well … especially when out of season. During Halloween, Christmas, or whatever holiday Blizzard decides to add some extra goodies to the game, make sure you stock up on those items by either putting them in your bank or storing on an Alt for awhile. Keep an eye on the Auction House to see how they are selling and usually within a month or so, you will be able to make a nice easy profit off of those items.
Class Specific Set Items
Get your hands on set items whenever possible. Everyone is trying to get the set for their specific class and they are always willing to pay top dollar for the remaining pieces they need. Below is a list of Set Names for each class.
Class Name
Druid Wildheart
Hunter Beaststalker
Mage Magister
Paladin Lightforge
Priest Devout
Rogue Shadowcraft
Shaman Elements
Warlock Dreadmist
Warrior Valor
Grinding
If you are one of those players that doesn‛t mind to Grinding, you should kill 2 (or 3) birds with one stone by grinding places where you can skin and/or complete quests in. It doesn‛t make much sense to grind just for the sake of leveling. If you can be doing quests, gathering, and grinding all at the same time, you will be able to make a lot more gold and gain a lot more experience so that you can get to the higher levels faster. Once you reach Level 60 (or 70 in Burning Crusade and up to 80 with Lich King) most quests pay out gold for the reward instead of experience. So if you are leveling faster, you will be making gold faster too!
Disenchanting
If your character‛s profession is Enchanting, listen up. There are some items that you can buy at the Auction House and make an EASY profit on all the time. How? The answer is Disenchanting. There are certain items that you can buy at the Auction House and then disenchant the item to get another item that is actually worth more than the original item. Blue items usually sell very well in the Auction House so unless it's BOP, you will probably want to focus mostly on the Green items when disenchanting. A couple of the best green items that I have found to disenchant are the Runecloth Boots and the Wicked Leather Headband. One of the items that can be obtained by disenchanting these is a Large Brilliant Shard which can sell for about 6 Gold a piece, depending on your server. If you do this 10 to 12 times, that alone will get you close to 75 Gold! This will also work for many other Green and Blue items. The type and quantity of your disenchant depends on the type and level of the item you are disenchanting. To help you identify which items you should disenchant, make sure you are using the Enchantrix Add-On so you know what items are worth disenchanting.
Character Transferring
If you don't have any sentimental ties to the server you are on, it can be VERY beneficial to you from a financial standpoint to take advantage of the free character moves from a populated server to a lower populated server. What this means is that you are now one of a small group of players that can provide the higher end items to the new players on that server. This will ultimately mean that the supply is low and you can essentially demand whatever price you want for your items. This is most helpful if you are on one of the servers that have been online since Day 1 and have a ton of Level 60s. To view a list of the servers you can transfer your character to, simply log in to your account and click the "Eligible Realms" link.
Taking Notes Keep a list in Notepad or Excel of what items sell good and which ones aren't worth your time. For the items that are worth your time, keep track of where you found them. If you bought them from a vendor or merchant, keep track of how much you paid for them as well. While this sounds like a pain to do, you'll be surprised at how useful this will be for you especially after you are making money off of so many different items. This is also helpful for when you are trading with other players outside of the major cities and it's not as easy to check the going rate of a certain item. You could also take advantage of Notes features in the UI to keep track of your notes in-game if you don‛t feel like going back and forth between WoW and Excel to manage them.