I'm not an expert on member money making, here is some freeplay stuff. Kill Hill Giants in Edgeville's resource dungeon. Find the limpwurt roots RS gold as well as bones. ~250k gp/hr last Summer. The Lava Maze is a messy maze. Only take the important stuff. This is the best method to earn f2p. I'm estimating 400k/hr however it takes time to collect muddy keys.
Mine adamant ore. I like to do this at the hobgoblin mine, wear the full batwing and shield, and you'll not require food. Hop worlds. The PKers here are so rare that you do not even think about them. You can also superheat the coal by mining it to make cheap RuneScape gold your trips last longer. I'm not certain if this is the best option however. 70 mining is required 70 smithing, if you are superheating. 200-300k gp/hr.