I mine Adamantite in bounty hunter worlds to get my EP up. After I mine 8 adamantite ore (worth 1.2k each), I kill hobgoblins until I get 2-4 limpwurt roots (2-3k each). I walk to the bank near the volcano, and I walk back (running when attacked by monsters). I only kill my targets, unless my EP is above 50 after killing one. Even with my deaths, and supplies factored in, I've made on average 200k gp per hour (When you kill your target in bounty hunter, they usually drop between 300k-500k worth of items. When I die in bounty hunter, I only drop 120k worth of items. Eating a full inventory of swordfish and pizzas costs about 10k). If my EP is above 50 and my meter is at zero, I spend time killing other people until my EP is below 50. They usually drop about 100k-200k in items, and its much riskier (these guys are career PKers, targets are usually poor sobs). I'll also merchant on the Grand Exchange. There really is no "GP/hour", it usually takes 4-10 days to complete one. I'll invest 10-20m in one item, and then sell it for 5-10% higher. So 1m GP in 7 days is 6k / hr :P