What is a good way to make money on runescape?

i have decided i want a phat, i have a bout 7m cash now. i would like to get the money so i cn get a santa of phat. i have 88 wc. but if there is some other way than that. my user is jojojo357 so high score me to see my stats. i am a member. i will not merch or flip. so please just some easy ideas to get 100m in 1 month please