Difficulty: Easy
Money Needed: 25,000gp or more.
Probably the easiest way to merchant, Willow merchanting is quick, easy and a reliable way to make fast, easy money. Lets start by going to Draynor Village, a small Willow tree-infested village south and a little east of Falador:

On almost any world, travel to the part with the willow trees (right next to the bank) and start buying all the willows you can afford, (don