Power mining iron at al kharid, 60k xp per hour. Never done it but hear it's the best way. Coal is 15k xp per hour (for me) but I'm typing on this forum while I mine. If you are high enough to smelt mithril, you can buy 22 mith ores, a fire staff, and 22 nats, and mine 4 ore, superheat a bar, and just keep doing that. Then if you like that method you can buy more ore and nats. I buy 1.5k addy at a time, but then again I'm crazy. That's 4k mage, 15k mining, 2.8k smithing per hour, not that good of xp (again, I look at the forum while mining), but you make some money as well (50k per hour?) instead of loosing a fortune.