Tanned green/red/blue/black dragon hide to earn runescape money
Requirements: have enough runescape gold to start it.
Methods: It is very simple but not very monotonous.
First you can go to Grand exchange to buy Green dragonhide / Blue dragonhide. And then go to the leather shop in Al-Kharid desert to leather skin, and then sold it out.
Profit: It depends on the purchase price and the selling price. In general, the price of Green dragonhide is around 1600GP, and the Glass-Green Dragon Paper is around 1900-2000. You can get about 2500 dragon skin per hour. If the purchase price is 1600/ea and the bid price is 1900/ea, You can have a profit of about 500K per hour.