1) The Gatherer

There are many things to be gathered in the game. This includes leather, herbs, ore, fish, linen, wool, mageweave, stones, gems, and so on. Moreover, there is much gold to be made here. buy cheap wow gold 

2) The Farmer

This is a profession usually taken on by those of higher (level 40+, usually 55+) level characters. To do this, you simply do instance runs or kill named bosses multiple times or do multiple runs through the instances in the chance of getting a drop. Before the patch that came out today (this was written the day the honor system came out), this is what wow gold almost all level 60 players did (since then, many lvl 60s have taken up pvp ? attacking the crossroads for example ? and then with the battlegrounds patch, they go to the BGs).

3) The Crafter

This is one of the players that says forget the gathering, I want to make things. To do this, you better have at least 10 - 20 gold ready to spend. The first 150 skill points into any craft, you will most likely lose money. In fact, I can almost guarantee it. The items below 150 aren't worth much or in demand enough to make wow gold serious cash. This can be said even with items up to level 225. However, past 225, it is pure gold. Be it Leatherworking, Blacksmithing, Alchemy, or Tailoring (note engineering and enchanting are not listed); there is money to be made. Reasons why:
Leatherworking - there are three paths. You can only choose one.
Someone will want what you can make due to only 1/3 of the people being able to make it.

4) Buy Low / Sell High

This is getting into the more complex of the ways to make your gold.
To be able to buy low/sell high, you will need an initial investment.
I suggest at least 10 gold if not 50 - 100 gold. But, 10 gold will get you started.

The strategy is simple - buy an item at a lower price than it is worth or can be sold for, and then turn around and sell it for that higher price.