I've noticed several posts on this and on other Guild Wars forums with questions regarding making money to buy that killer item. Following, I thought I'd give you all my two cents on the subject, and hopefully, someone will find it useful.

The first thing to remember when trying to collect cash for that new armor, a guild hall or whatever else you need, is that there is no generic template for making money. There are several ways to go about, and basically, it all depends on which way you prefer.
The easiest way of getting some gold, is to just play the game. This worked out perfectly for me. The trick is, to sell everything you can get your hands on, except from salvage items, max stuff, and weapons with perfect or near perfect mods (salvage these, and sell them to other players if you have the patience). Don't sell "regular" items to players though, but to merchants. This saves a lot of time, and is generally just easier as long as we talking about non-max items. When my elementalist reached the desert, she was carrying around 40k from just playing the game.
Another popular approach to money making, is off course, farming. “What am I supposed to farm?” you might ask. The answer: The highest level mobs you can solo. And you better be able to kill off lots of them at a time too. There are of course some mobs that drop more desirable items than others, and that is the tricky part; finding a good farming area IE; an area with mobs that drops “good” stuff. I've found that the best way to finding a good farming area is once again, to play the game. When you stumble across a nice spot, you will know. Just look for places with high concentration of mobs relatively close to the zone portal, and try to farm them to see if it works out. I've seen a lot of topics lately saying that most farming areas have been nerfed, and while I have noticed a small decrease in drops on my favorite spots, they are certainly not completely nerfed. I can agree though, that when Anet replaced their nerfing-bat with a nerfing AoE with 75% drop penetration, it's gotten a bit tougher to find good spots, but far from impossible.
Speculating in the marked can also give quite a profit, but this requires you to spend time watching prices and finding out when to buy/sell. You can earn a lot this way, but you need to have some money to start with. Personally, I prefer farming or questing, hence I have little experience with this approach and not much to say about it.
The most important thing to remember when trying to save up to that awesome item, is don't spend money on unnecessary things. The only thing you should spend your money on while saving up for something, is salvage- and identification kits. Another thing to remember, is that collectors are awesome. They give you everything you generally need, at least until you can afford that godly sword or whatever. It isn't exactly hard to collect 5 items either, so it's worth it even as a more temporary solution.
Well, thats about everything I can think of right now. I hope someone will find this useful.