Some tips for how to make coin in the world of Norrath
Harvest and sell rares. Some people might say that the prices of rares will drop... well it does and then it goes back up. Prices fluctuate for pretty much anything on the broker.

Sell those collectibles on the broker.

Tradeskill and sell your mastercrafted stuff.

Buy low, sell high. Sound familiar? Well, the game economy is an economy like most other ones.

Distinguish what items might sell well enough on broker to bother selling them instead of vendoring them. Most things sell at least somewhat better on broker, but some things just are plain vendor trash.

Sell to the right npc... if you really want to get the most out of your vendor trash, take it to someone you have the highest faction with. If you are going to sell a lot and the items are worth at least a couple of gold, it really starts being worth the trip.

Get a house. This cannot be stressed enough. When items start costing up to a plat then broker commission starts to hurt, and people often bother taking the trip to your house to buy it. Plus sometimes you can mark your options higher and still be cheaper than the other person.

Get the most bang for your buck. Kelethin might not be the travel hub, so I'm not so sure that is any better than Qeynos in that aspect. Neriak is cheaper to live in than Freeport and just about as accessible. So I would probably recommend Neriak if the rent is an issue. Many people seemed to have moved to Neriak these days as well. However, one thing to keep in mind is that it appears impossible to sneak into Neriak, so if any good toons want to buy from your house there, well... they could most likely expect a repair bill. It is easier to sneak in Freeport.

This one is obvious... hunt nameds.

Don't destroy your non rare harvested stuff! The prices on some of the roots often get ridiculous, especially succulent roots, which is used heavily in tradeskill tier 6.

Have fun!