Do just a little bit of farming runs
I've already started playing with a different accounts, and while I like the new username I have chosen, I'd like another. I'm presuming my high level accounts were hacked into OSRS gold, because the email my current high level accounts was on was inactive but I believe at level 50+ your account is not deleted for inactivity, no? Either it had been waxed, or I don't have any clue what happened, but I don't have any character name. Unless I changed the email for that account, in which case I do not understand how I'll recover that particular account.
Do just a little bit of farming runs. Even if you just do one per day and just 1 region, you'll earn money steadily (that is what I do, also that I have an 8mil bank). You probably could train power on lower demons, they now drop ashes that are worth ~600 gp each, together with some elchable items. Guthan's might help greatly, but you could not afford it for a while. Kill them at the Karamja place next to your lave thingies.
Every once in a while, look for an evil tree to kill. They have a nice reward worth a little, and then find a yew tree to cut down as you've got the auto-banking effect . You get the auto-banking for some amount of minutes based on how much you helped kill tree.
It is by no means the quickest route to 10M but it's steady and will get you there eventually. A goal in this way is not simple because the temptation will always be there to spend it on crap but to perform it using one of my methods: Require 10k and buy oak planks for -5percent and see if you get some. The 10k is simply a tester to see if they purchase and you ought to wait 5-10 minutes.
If they do not buy then improve your bidding 1-2gp until they do purchase. Sell 1-2gp under centre cost. Generally you will acquire 10-12gp for every oak plank (which means you should place your buy price at 13-17 under mid) you do that might not seem like much but the next time you'll get more, and more and cheap RuneScape gold more. . .before you know it you'll be trading 25,000 regularly and pulling in 300k per trade.