so i noticed a couple things imparticular that make you good money, so why not tell you about it??
1.) if your first starting off, and your first priority is to make money to save for a specific item, armour, ect. then try doing Thieving, it is simple and a great way to make money.
2.) fishing is a great way to make money, it is similar to thieving, all you do is sit there and fill up your inventory with items and then put in bank, or sell to a store! The best paart about fishing is that there is a bank right next to the fishing spots.
3.) Level up slayer as high as you can preferably to 90, and then go to slayer tower, all of them have good drops, just dont forget, BE PATIENT! thats one thing that will get you great items, for better drops it takes longer to to get them.
4.) kill bosses that drop rare Armour and weapons such as: the corpal beast, all godwars dungeon bosses, tormented demons, dagganoth kings, chaos element, and kbd. (high combat required)
I will update some more stuff later