Put muddy keys in the Lava Maze. Only take the most valuable items. This is the best way to earn cash from f2p. I can make RS gold 400k/hr with this method if I'm good. However, the muddy keys cost a lot and take time to buy. Utilize a gem bag to get maximum efficiency. Mine adamant ore. I like to do this in the hobgoblin mine, wear the full batwing and shield, and you'll not need food. Hop...