I usually just farm by using potion of luck
As a 585 hunter I can farm:
4-7 spirit of harmony per pot
betwen 50-90 treasures
150-250 windwool cloth
2-3 stacks of white trillium ore
2-3 stacks of black trillium ore
1-4 stacks of ghost iron ore
1-3 stacks of exotic leather.
20-40 green items
Unknown amount of grey items
Sometimes blue or purple quality items.
I undercut badly, so I sell 1 stack of cloth for 16g per stack, ghost iron about 30g per stack, black and white trillium for 5-6g per ore, I vendor all grey and green items and I make leg enchants with leather, sells for roughly 140-150g per.
example sales:
1x leg enchant : 150g (I usually only use the 1 a day transmute)
40x black trill : 200g
40x whit trill : 200g
10 stacks cloth: 160g
30x greens : 600g (took an average of 20g per item, might be a bit off)
greys : 300g +/-
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total amount : 1600g in 1 single pot, averaging at 4.8k in 1 single hour, of course you need to calculate repair costs and pot costs as well.
I did not count spirit of harmonies into this! nor did I count pure gold from chests and mob drops because I haven't really checked how much I get.
You can choose between being stationary at windward isle, farm keys in vale of eternal blossoms (both which are ok spots) but personally I earn a lot more doing sra'vess routes as I can pull so many more mobs there.
Wher do you farm when doing the potion of luck thing?
I did this on horde side (I'm always alliance) when I decided to roll a horde hunter. I got a level 1 or 2 or something up to Org. Starting with no money, no bags, I started leveling my hunter. ANYTHING I ran across that wasn't vendor trash went to the bank toon. By the time I hit level 85 (was in Cata) on my hunter, I'd made over 50,000 gold just from AH'ing everything I'd found. The hunter was also a skinner and enchanter, but most of my money came from mob drops - greens, gems, random patterns and whatnot. I made so-so gold from DE'ing all the BoP crap I got as well.
I ended up giving the gold to a friend I'd met on horde side, deleted both of them and went back to alliance. In MoP, I decided to do it again, I wanted to make an 85 twink Pally with the MoP blues. By the time I hit 85, I was rolling in almost 10k gold A DAY from all the greens I'd found and sold for ludicrous prices on the AH because of transmog.
Will you make gold quickly? Not really. But it can bring you in a lot of gold over time if you do it right. Like this guy said, just freaking AH EVERYTHING you get.
Get Auctioneer/Auctionator/Trade Skills Master or whatever the current versions are, and play the AH. You will have far more than 100k in no time.
You have used them wrong then. I'm making ~12k gold daily for 20 minutes of ah play (except when new guys show up on my market and I need to put some pressure on them to learn their place). That is with one profession, when I'm pushing with all I have I can get to a 30-40k daily but that is boring and too much work for my lazy ass. And no, it would not be possible without addons.
100k ? Gotta farm Poseidus
That might actually be the slowest way
You'll come to find out that farming is actually counter-productive if you break it down- labor=time=money lost/gained - that is the formula to max your profits in anything, RL or in game. As the expansion comes to and end Xmog usually picks up a tad. Not much but enough that it is almost worth looking at. Check the smaller markets like battle pets/companions/mounts/tcg postings ect.
During the end of an expansion people have pools of gold they have been sitting on throughout the raiding tiers or pvp seasons that they don't know what to spend on. Some save but a lot of them buy stuff that they have wanted to. A lot of people miss out of things like battle pets and mount collecting or farming due to raiding times so this increases demand due to a wide array of different reasons.
While selling everything you pick up is a nice plan in theory - in action can be a bit hit or miss. Sometimes I see things posted up with a going price of less than what it would vendor for which is obviously not right. Also realize that it costs to post on the AH. There is a very small posting fee, kind of like ebay, that is required to post an auction. However this can be like one starbucks/DD coffee a day...it seems like only 3-5 bucks isn't much but it adds up quick. If your inventory is well over 300 items, which isn't a lot at all once you start getting serious about hitting your goal, you can be looking at a decent $ out of your own pocket. Mixed with the fact that nothing is guaranteed to sell it is just something you should really keep in mind.
While I can sit here and tell you every single market that could potentially be in demand if I used other servers as a comparison I really wouldn't be able to help you unless I knew the server/faction you played on. But I hope some of those tips helped if you are still searching on how to increase AH profits.
My advice would be to enjoy the sun and rest of summer. Come back in expansion and play hard for a month.
Be prepared as well.
As someone who knows how to make gold, then id suggest theres a good time to make easy old and a bad time where you are flogging a dead horse or its qyestionable whether its wrth the effort.
If you insist then find as many niches as possible. Read up but also put the effort in. Its so common on these forums people asking advice and then they never bother to learn/ research and never put the ffort in then fail to realise why they don make as much as they wanted.
Wanted to stockpile 500k before wod and I hit that early this week at 515 now. I just utilize having every profession, this takes a lot of time initially to set up leveling alts etc but I did it early in the expac and now I can make a steady stream of gold, no real "massive" items over 2k or anything. I like to sell a bit of everything, in this way I can never flood a market and I find that more of my things sell. Much easier to sell say 2 leg armors belt buckles a day than 20 gems of the same kind. I must post a couple of hundred things a day but I'm not flooding any one market. Another good point of having every profession is - I pay for nothing, my expendature is zero aside from any mounts I want to buy. I don't really like AH watching as much because if I'm doing other things I'm at least out in the world playing, but there are a few items I look for and those handful alone have gotten big payouts for sniping them low.
Depending on your server, it's true that playing the AH can net the best results, but right now a lot of people are doing it and you basically have to spend your whole time scanning the AH which can be somewhat boring. Pets and mounts are multiplicating at a really fast rate and the prices keep going down. While it is true the elite core is hoarding gold, the casual demographic is leveling alts and trying new classes. I make roughly 100k a week just by farming and selling enchants/gems/glyphs, granted that I have every profession. You dont need a full-heroic geared toon for that, my main farmer is in grievous gear and does just fine. You can check some guides on twitch and youtube, Umren and Peck namely have some good spot to farm. Of course it requires you to like farming and have some free spare time. As previously mentionned, learning the basics of Auctioneer and TSM helps greatly and reduce your time wasted on the AH if you have a lot of things to sell.
I made my first million using Auctinator, after learning how to use TSM the gold income was a lot higher per hour.
It might not have that result for you, but for me it is the opposite of overrated.
OT: A lot of great suggestions have already been given in this thread.
What you should never forget is that everything adds up. If you cba to scan the ah just do stuff like the Isle of Thunder treasure run, an average of 600g per run for me for +-15 min. Having every profession helps a lot like mentioned already.
Transmog runs can also give you a lot of gold, like the pets from Karazhan. Doesn't matter what class you are, you need Gorehowl!
Knowing how to play the AH is the best advice. Knowing how and when to undercut to get prices to go down, then buyout and relist higher. Knowing when to buy bulk in trade and relist/craft+sell. It takes a little experience and patience.