First of all, get your magic high enough so you can use Telekinetic Grab (this is about level 33 magic). Then get lots of Air and Law runes. Finally after that, go to the big bank in Varrock, go downstairs and go to the gate, then use Telekinetic Grab on the coins or the other Gold Stuff. Then sell the Gold Stuff. This way you'll be a millionare in no time!