You can come to the Grand Exchange

A rich account with much gold should always be favored by everyone . While it is not that easy to make much gold . With high level attack , strength, and defence, prayer and summoning , you can be melee ; while you can make much money through training the skills like cooking, woodcutting, fishing, fletching, mining, fire making, smithing, hunter . Training the skills is not only one way to make money , but also provides you a lot of fun . When you are training mining , you may find some strange ores…

There are many ways for you to make money , if you are not a member ,but want to make money fast , you can try the following ways :

First,you can try to cut yews trees,with woodcutting level over 70 ,you can makw 60k gold per hour;second,getting zamorak wine with telegrab in chaos temple if your magic level is over 31(seems to be that level),you can make 100k gold per hour;third,digging rune ores with mining level over 85 ,it seems to be 500k to 1 m gold per hour;forth,buying coal and iron ore to smith steel bars , you can make about 100 k ;fifth, if you alredy have several million of gold , you can come to the Grand Exchange , and you can also make much gold. And if you are a member , you need to spend money for many items , while you can also make much gold with many more ways then .

Anyway, these are just suggestions, you can find  ways which fit you best and have much fun with this game , not only in making money , but also in fighting with others , or something like that .