up to 500k p/h without skills / 1m+ with skills

This is NOT my guide, i take no credit for this.
All credit goes to "soul psyche"

Table of Contents
1 - Making money with Smithing
2 - Making money with Summoning
3 - Making money with Mining
4 - Making money with Fishing
5 - Making money with Woodcutting
6 - Making money with Combat/Slayer
7 - Making money with Miscellaneous

Smithing

1) Making Cannonballs
Profit: 100k+ an hour
<>Dwarf Cannon Quest
<>35+ Smithing

Items:
<>Steel Bars
<>Cannonball Moulds (from dwarfs on the mountain west of Edgeville)

What to do:
Smith the steel bars into cannonballs at a furnace. The closest to a bank is the one in Port Phats and after that I would use the one in edgeville.

***Under this section are several ways to make up to 250k in 15 minutes, but you can only do it once per few hours or once per day. They too are designated with *** after their name..

Summoning

1) FFDN (Up to 1m+ per hour)
(Stands for "fast free double nats")
<><>57+ Summoning required
<><>50+ RC helps

Items Required:
Pure Ess
Preferably as many runecrafting pouches as possible
Spirit Graahk pouches
Rings of Dueling
Probably weight reducing gear
Nature tiara or omni tiara

What to do:
Join the clan chat "****" (not allowed to have it on here.... but if you go to W36 thats normally where they are) which stands for fast fast double nats, it's an assisting clan which matches people who want to make money and people who want to get fast rc xp who have 91+ RC for double nats.

All you do is have as much ess with you ass possible, your graahk summoned, and a ring of dueling on. Use your graahk's teleport, run to the nature altar, req assist from one of the people there with 91+ RC (they will have a uniform normally to show they have the level), get all your nats, tele to castle wars, then repeat.

2) Fruitfalling
Profit: 600k+ per hour
<><>69+ Summoning Required

Items Required:
Fruit Bat pouches
Fruitfall scrolls

What to do:
Well, there are a few ways to go about this. Basically, you set your left click option to use scroll or whatever so that it uses fruitfall. You want to be near a bank and you simply cast it, pick up the papayas, and bank them. And keep doing this. However, there is the variable of what to do when your fruit bat is recharing the special attack. What I did was fish for trout + salmon in Shilo. However if you want to you can just alch or do something else to pass the time..

Mining

1) Mining Pure Essence
Profit: 100k-150k per hour
<>Level 30+ Mining
<>Quest: Rune Mysteries

Items:
<>A Pickaxe
<>Runecrafting Pouches help since they can store Pure ess

What to do:
Go to Aubury in Varrock and teleport to the mine, mine pure essence, and bank it. If you have 66+ Mage I'd suggest using the Mage guild's Wizard Disentor to get to the mine since it is closer to the bank. If you have the pouches use them to store more essence per trip.

2) Mining Gems
Profit: Up to 300k per hour
<>Level 40+ Mining
<>Need access to Shilo Village which requires quests

Items:
<>A Pickaxe
<>Gem Bag from dungeoneering would help

What to do:
Simply go to the gem mine, get some gems (emeralds, rubies, and diamonds mainly) and bank them. Then repeat. It can get crowded so you can look for a more empty world or try out for a PvP world, but you can get killed there so not too highly recommended. I did it back when there was the whole 3 item safe thing which made it much safer to do....

Fishing

1) Fishing Lobbies
Profit: 100k an hour
<>40+ Fishing Required

Items:
<>Fishing Cage

What to do:
Just fish for lobbies at one of the many areas, the fishing guild or catherby is best. Sell them raw for best profit.

2) Fishing Swordfish
Profit: 100k an hour
<>50+ Fishing Required

Items:
<>Harpoon

What to do:
Just fish for Swordfish at one of the many areas, the fishing guild or catherby is best. Sell them raw for best profit.

3) Fishing Monkfish
Profit: 125k an hour
<>62+ Fishing Required
<>Swan Song

Items:
<>Fishing Net

What to do:
Just fish for Monks in Piscatoris. It's still how I fish since it's decent xp and cash.

4) After Monks, you have sharks and you have figured out fishing well enough to do it on your own! Good luck.

Woodcutting

1) Achey Logs
Profit: 80k+ Per hour
<>Level 1 Woodcutting required

Item:
<>Highest level hatchet possible

What to do:
South of Castle wars are achey trees which you can cut down, and bank the logs. Makes a solid 12k+ per hour.

2) Eucalyptus
Profit: 90k-200k per hour
<>58+ Woodcutting

Item:
<>Highest level hatchet possible

What to do:
Use the Mobilising Army teleport on a ring of duelling to get to the area. Then just cut the Euca trees and bank the logs. There are ways to trap the creatures there so that they do not attack you.

3) Yews
Profit: 100k-200k per hour
<>60+ Woodcutting

Item:
<>Highest level hatchet possible

What to do:
Cut yew trees. Pretty simple. They're located all over, its just a matter of finding some close to a bank that are empty.

4) Yews/Magic
Profit: 100k-400k per hour
<>60+ Woodcutting
<>80+ Summoning
<>60+ Farming

Item:
<>Highest level hatchet possible
<>Yew/Mage tree
<>Hydra

What to do:
Plant a Mage or Yew tree, then after it is fully grown cut ir down. After it falls, use the hydra to have the tree instantly come back. Basically you get a private tree that you don't have to wait for it to respawn. pretty legit..

Combat/Slayer

1) Aviansies
Profit: 100k-400k per hour
<>70+ Range
<>70+ Defense

Guide here:http://www.wemakegepe.org/guides-f7/money-making-with-range-via-avianses-t19.htm

2) Slayer
Profit: 50k-1m per hour (depending on level)

3) Green Dragon Hunting
Profit: 400k-700k per hour
<>Melee: 60+ at/str/def
<>Ranged: 60+ range, 55+ slay highly recommended

Items:
<>Melee or range gear
<>Games Necklace
<>Anti Dragonfire shield
<>Antifire potion if lower leveled
<>Ring of Kinship

What to do:
Basically, kill them. Collect bones and hides and other valuable drops. Bank using ring of kinship and then tele to clan wars to go back closeby,

Basically, just train it. It makes bank..

Miscellaneous

1) Collecting Blue Dragon Scales
Profit: Up to 400k per hour
<>70+ Agility
<>or 65+ agility and a summer pie

Items:
<>Weight reducing gear
<>A Beast of Burden to carry more scales

What to do:
Go to the dungeon in Taverley, use the shortcut to get to the scales really fast. Collect the scales as they spawn and bank them when your invent is full.

2) Buying Unfinished Broad-Tipped Bolts***
Profit: 100k-175k in minutes
<>I think you need to finish smoking kills to get access to them? Not suree

Items:
<>200k gp

What to do:
Go to your slayer master, buy the 3k unfinished broad tipped bolts, sell them on the GE. Then do it again in about 24 hours. Simple. Fast.

3) Managing your Kingdom of Miscellenia***
Profit: 100k+ a day with no work
<>Need Throne of Misc done, I suggest Royal troubles too

Items:
<> Hatchet/pickaxe/harpoon/cage
<>750,000-7,500,000 gp

What to do:
Simply put the money in your kingdom's coffer by talking to Advisor Grim (or something like that, not positive on his name), and put as many of your workers on herbs as possible, then put the rest on raw fish. Check it every few days and put money in your coffer to replace what is being taken out. It's a solid profit.

4. Collecting Black Scimitars
Profit: Up to 500k per hour!
<>No Requirements

Items:
<>B.O.B. if you want

What to Do:
Go to the second floor of the ardy castle in the southwest area, and pick up the black scimitar. Since they have a respawn time of over 12 minutes, you want to log out and log in to a new world. Since this is fairly unknown you don't have much competition. At 5k per scimitar and it taking about 15 minutes to get an invent full, that'd be 560k per hour.

5) Farming Herbs***
Profit: Up to 250k in as little as 15 minutes
<>38+ farming

Items:
<>Toadflax or Avantoe Seeds
<>Secateurs (Preferably magic from the fairy tales quest series)
<>Rake
<>Spade
<>Fally Shield 3 (suggested, not required)
<>Supercompost
<>Teleports to the patches (Patch locations HERE)

What to do:
If 38-55/60 farming plant Toadflax, if 55/60+ do Avantoe. The reason I suggest these is they are cheap seeds that yield valueable seeds. And I recommend doing Toadflax through at least 55 because the higher the level, the more herbs you get per seed. So you get more Toadflax than you would Avantoe at level 50. First, make a round planting the seeds in all the patches you can after laying down super compost. Wait 80 minutes, and go back and harvest. Some may have died of disease, however it's not worth the time to pay attention to them. After you harvest each patch, lay down more super compost and plant more. Doing this with Avantoe at level 70 farming I can make up to 250k per run in Avantoe.

All credit goes to "soul psyche"