Now, everyone gold-maker should make sure they have a guild bank. It is the most biggest storage vessel available, with a total of 784 slots available for 39350 gold.
But did you know that a level 25 guild can make you a lot of money per week. Every week I made a few thousand gold from my guild, which is just for social people after the leveling and guild perks no doubt. It doesn't take much effort to get to this level either, just time to sit there spamming out invites.
Okay, so the first step is getting a level 25 guild. If you don't do much else in game besides gold making, your best bet is to buy one. Typically, a cheap guild is around 10k on my realm. Prices depend on the number of people, guild tabs and sometimes even the name. Make sure you check out the guild bank too, in case there are hidden recipes and items worth a fortune. Sapu over on the Consortium forums made a guide to help with this.
A level 25 guild will start making you money as soon as you have members. To help with that part, you will need to send out guild invites on mass. Now, usually that means you will end up with a lot of declines if you aren't from a max level guild. Luckily, everyone wants the perks so they join.
I suggest using SuperGuildInvite to send out the invites. It is a great little addon, and it makes sure NOT to spam people with invites. Once it sends an invite to the person, they get black-listed so they don't get another. It's brilliant! Make sure you include a little synopsis of the guild in your message.
If you prefer, you can level the guild yourself however. It does take a bit of work, but it certainly is possible :)
Encourage people to raid, dungeon, scenario and do Rated Battlegrounds in a guild group and you will get even more gold!