Get your character's mining level up to level 38 by mining iron, etc. Then, go to the Barbarian Village and mine coal from the rocks, which you can sell for 100 to 300 GP per piece. You will also occasionally find a gem (from least valuable to most, sapphire, emerald, ruby, diamond) which can be sold for good prices.?
Go to the house outside of Lumbridge and collect Iron Daggers on World 13. Also, defeat Goblins for items that can be sold or gold, which is common. Sell the daggers for 14 gold or less at the market.
Easy way to get money is to go to the church in lumbridge. Once you are in look for a girl and attack hear she eill drop iron daggers, money ranging from 3-41 coins, fishbait, and sometimes nifes and swords.
