Ill tell you my ways of making money-1.get a brass key and go to the shack just south-west of the grand exchange go in shack down ladder then follow the path from the ladder to a caged off sectsion thengo through the door then take a left to were chaos druids are kill them they drop about 70k-100k herbs each time you take a trip there they are lvl 13.
2.my second method of money making is to kill blue dragons in taverely duengeon bring a dusty key. go gon ladder to dungeon just south of taverly follow the path s untill you to some kind of floating battleaxes ignore them go strait then take a right then walt just a bit then take anothere right you will pass some chaos druid an somre lesserdemons then go to the caged off secsion use dusty key on cage dore then there will be blue dragons and baby blue dragons depending on you lvl i would use range or mage because there lvl (111) and dont forget anti-dragon shield.
3.My favorit way of making money is to do clue scrolls just kill a monser like rockcrab or person for lvl 1 clue kill guards or white or black knights for lvl 2 ordragons or greater or black demonds (not lesser demons they do not drop clue scrolls) then go to a website like rune hq and click on treasure trails to help with your clue scroll.
happy Money Making :)