Ok this is my first guide i ever make, sorry if it's already been posted before but I've been using this to make major amounts of gold.
What you need:
1. A ''scammed'' account {Yes, you need an account which you got from someone else, lvl 70 char on this acc is prefered}
2. A friend to help you. {Of course someone you trust}
What you are going to do is:
1. First you find what mats you want to scam, this can be enchant mats {http://thottbot.com/s27984} or tailor mats { Thottbot World of Warcraft: Spellstrike Pants, Thottbot World of Warcraft: Whitemend Hood and so on since there's alot of tailor stuff you can choose from of course choosing the most expensive us a plus }
2. Now! Of course you can't craft the stuff you're going to make so, you find someone who can and make him link you the [Tailor: something-or-other-expensive tailor recipe] where you can see the mats and what it creates, you know what i mean. If possible make your friend be the one asking for it, since it will make you a tad less suspecious.
3. Ok, we got all the components to start doing this, find a spot where you will be staying {Recommended is Ironforge since alot of people are there}.
4. Now you find whatever spot to be, the best way to do this is to find someone who yells in trade, 2:[Trade] [Nuub]: LF Spellstrike/Mongoose tailor/enchanter.
5. Go whisper him, meet up with him somewhere where there's people of course, make sure your friend is nearby blending in or whatever, as long as he's close. Of course taking a money fee for the nether will make it more believeable for some people, this is up to you.
6. You will trade with him, get mats and whatever, you friend will trade you{Not the other way around!} and get mats, gold and whatever the fool gave you.
A little tip: Don't stay logged in on the toon you're scamming with, log another char and watch the trade channel for people who need enchants/tailor stuff made.
Conclusion:
This worked great for me, i lvled my toon on my main acc and when i saw someone LF enchanter or tailor simply relog and have your friend close.
I earned 4x spellstrike mats 1x mongoose mats and 1x whitemend with 1 account. Currently trying with another acc and having succeded 2x times with the spellstrike.
Of course this may seem as common sense to some people but I've earned a shitload of gold doing this :P Nearly 4k gold in 2 days.
This is something you can do if you have a acc laying around noone uses anymore or whatever, go have fun.