This is my personal experince in guildwars money making from the start which started in 02-15-06.
Started off dirt poor stuck in the presearing thinking to myself, i know nothing about this game. Let me search the internet

found gameamp.com, then found this website.

After reading about the game first, then i started to play better.
Made a Warrior since most of the runners were all warriors, made around 200k in around the first month of playing the missions and running people to the easy spots.
Then i got to droks and noticed all the people selling parchment. So i went online and read what made parchment. Bought all the wood i could get my hands on, made parchment and made around 150k during the first week of doing that.
After that i took my warrior and starting farming the trolls outside droks to get more wood to make parchment. After getting a fellblade or 2 as drops, i asked around what are these worth. sold the first one for 50k and the second for 30k. Then a light switch went off in my head. People love gold items, where can i get gold items???
Then i started to chest run ice floe, and other shiverpeak chests, because people in town were selling the keys cheap (thanks bot farmers) After getting a couple of good sword mods and axe mods i made around 500k total in my first 2 months after spending it on 15k armor and what not.
Then this new game called Factions was coming out. I bought it the first day it came out. Then i thought to myself.... gee what would make me alot of money here... materials for the new armors that people wanted. So i jumped to all the missions spots in the desert and ring of fire area, saying WTB tanned hides, and cloth will buy all you have pm offer.
After buying a ton of tanned hides and cloth for around 12g each , i went to droks and sold them for around 26-27g each making around another 200k in 3 days of doing that.
Then after making cash there in propchies, travel to the new land of canthna and noticed that rune trader was out of all the runes for the new classes. Also there was like 8-12 people just standing at the trader selling runes for riduclous prices. Then i thought to myself... hmmm how are they getting those runes??
After standing at the trader and clicking it over and over really fast i noticed that when it flashed, something new was added (i.e. new rit or sin rune that was privosly sold out) bought a sup dagger rune for like 4k and sold it for 40k to the guy saying WTB sup dagger 40k

So i called it rune snipping and did that for 2 weeks making around 400k doing that.
After getting bored with money did more missions in factions untill i got to the kurzick side where i opened a chest and this gothic axe dropped. I was a req 9 15^50 and i thought it looked so cool. still have that axe to this day.
This new axe was so appealing and since no one was selling it, i firgure i could get a ton of money for it. That began the chest running era of my guildwars life. I heard that people that owned kurzick towns got keys for cheap, so i joined LUST back in the day. Then after buying some keys and looking for some spots to run i found melandurs hope.
If you run the 4 spots and each one of your party got the spots and died you got money, faction, xp, and chests along the way. Taught this to my guild and was born the FFing era of faction farming Melandurs hope.
So FFing there and chesting at the same time got a ton of gold drops while getting some xp and faction towards my guild holding house zu heltzer. Once i got my first gothic dual axe rq 8 15^50 i about crapped my pants. I got a price check at 100k +65 ectos for it. Hmmmm with all these good items here i can make a ton of cash....
So i started chest running everything, raisu palace, melandurs hope, napiu for all those lovely gold items that people were paying a ton for.
After 3 months of chest running i now have 1.2 million in storage. 250 of each material, except 167 ob shards, 35 rubies, 65 sapphires, 22 monster claws, 22 D Steel, and 2 monster fangs. Have made around 8-9 million chest running, and spent over 3.5 million on keys. The saying is true it takes money to make money.
So after all that i have done to make money, i never farmed the elite missions, never did underworld 55hp monk farming, never did tombs. Just pure smarts with the market and what is hot. Getting those things to people when they want them ( parchment, runes, gold items ). The key is to go where the money is. If a sephis axe is going for over 100 ectos find where to get one. If a rune is selling for 40k find out where to get it. No one is more lucky then the next guy. They have the same chance of getting something just as you do. Some are just smarter then others :P
And on the last note here are some predictions of what is going to make money in the near future.
1. Dervish and Paragon runes
2. Dervish and Paragon materials (tanned hides, iron, and other rare materials)
3. New greens in Nightfall will demand a high price.
4. Gold spears and scthyes with energy and 15^50 low req items
5. So in detail anything having to do with Nightfall right now will earn you a ton of cash, so stock pile up those materials, get ready to run those chests in nightfall, and stay close to the rune trader to buy those new runes.
Raca Reznor,
A Short Story About Gold and Me