One of the best things you can do as a gold maker is make relationships or ask for deals.
For a jewelcrafter, it may be finding a farmer who is willing to sell ore to you directly. Usually they are willing to give you a good price for buying all of it. It also keeps that ore from going to your competition. It is a win-win.
Another thing you can do is try to buy out your competitors if they have strange posting patterns.
I have a JC on my server that only deals in red gems. He will post around 40 of each cut, in stacks of 1,2,3,4,and 5. He does not deal in other gems. The other thing he does is instantly undercut down to 125 if red gems are higher.
I sent him a letter to see if he had the other color gems for sale. Apparently he got a ton of ore and prospected it for cheap prior to 4.2. He then vendored everything that wasnt an Inferno Ruby or Carnelia (DOH!).
Well, I am currently trying to work out a deal to buy the rest of his 400 plus red gem stockpile. This should put me in a good postion to make tons of profit if I get them for a nice price. Without asking, he would have just continued as is. Now I may be able to make a nice mint off of those gems.
This ties into the "Know your role and shut your mouth" post a couple of days ago. Had I been a dick to this guy about his tactics, there is no way a deal would have been possible.