I would recommend using OSRS GP an emerald/broad (e) setup, start by using the emerald (e) to poison, then switch to broads to finish it off. Each kill is worth around 20k or so. I myself do 2 kills every time (using prot and eagle eyes at times) melee occasionally) then return to the home port, recharge at altar, use the fally portal and bank and go back in time in time for the next one...