Free-to-play Combined training

Combining skills can be an efficient way to train on RuneScape. Doing this can add add a bit of afk time in an otherwise fully non-afk skill and it can also increase your exp/hr. This guide will show many different combined exp styles for almost all skills. The methods are 'on site' methods. They don't include things like fishing and then cooking sometime later, only skills that are done then and there. Please note, this guide only includes F2P skills & styles. P2P most probably has many other methods and faster exp/hr opportunities. Dungeoneering training will not be mentioned as it includes every skill.

The skills are listed in alphabetical order. The methods will be put under the skill that gains the most exp/hr compared to the other methods.

Attack/Strength
Attack and Strength are always trained with Constitution. On top of that, players can also train Prayer if they choose to bury the bones/scatter the ashes.

Karamja
One way to combine attack/strength with other skills is at Karamja. The way to do this is to go to Karamja with your best armour & weapon, a hatchet, a tinderbox and a lobster pot or a harpoon. You can fish raw food and cook it on Karamja island. After you get a full inventory of fish you can go to the lesser demons inside the Karamja volcano and fight. When the food runs out, repeat the process. This method trains a whopping 6 skills at once and can be trained indefinitely (without banking).

Almost anywhere
If you are a 1 defence or a low defence pure you may get beaten up a bit. So instead of repeatedly banking for more food you could choose to pass the time while your health is regenerating. An example of this is killing ice giants or warriors south of Port Sarim. When your health gets low you can step outside the cave and woodcut/firemake the willows along the shore. Also before you go back to bank from your killing spot you could collect and inventory of resources. This could be done at Falador south gate. After running out of food you could cut an inventory of yew logs before returning to the bank.

Constitution
Constitution is passively trained with Attack/Strength, Magic and Ranged.

Lumbridge, Barbarian Village, Karamja & other places
If you are powerfishing in an isolated location you may want to consider cooking your fish. The way to do this is to bring a tinderbox and hatchet to your fishing location and cook your fish on your own fire. When finished cooking them, drop your fish and repeat the process. Doing this gives faster exp/hr than just powerfishing alone. This method trains 4 skills at once and is a completely free way to train cooking. If you don't want to bring a tinderbox and hatchet; or think they take up to much space in your inventory, there are fires in the helmet shop and the hall in Barbarian Village. With the addition of the toolbelt, one can carry both a tinderbox and a bronze hatchet without losing inventory space.

Champions Guild
One good place to train cooking is at the champions guild. You can kill the chickens on the balcony outside with your preferred combat style and pick up the raw chickens. When you have a full inventory you can step inside and cook them all on the range. If you bury the bones and fight using defensive attacking with magic or ranged you can train 5 skills at once.

Cutting gems while powermining
If you choose to powermine (mine ores then drop them) then taking a chisel may be a good decision. Instead of dropping the gems you mine from time to time, you can cut them and gain crafting experience. Every 1 million mining experience you will gain approximately 5,000 crafting experience in cutting gems. With the addition of the toolbelt, a chisel may be carried without losing inventory space.

Defence
Defence can either be trained directly through melee or passively while maging or ranging.

Woodcutting & Firemaking
This is one of the most obvious ways to combine skill training. Basically you bring your best hatchet and a tinderbox to your desired training spot. As you don't need to bank it's recommended to train in an isolated spot. Some good options are east Lumbridge pond (Use the path for firemaking), Daemonheim woodcutting island, and south of Rimmington.

Magic
With high alchemy, magic can be trained with only using up 2 inventory spaces (Nature runes and items being alched). One way it's trained is through teleporting. Teleporting shouldn't be trained solidly, only when you're getting from A to B. A weeks worth of teleporting (depending on how often you visit the Grand Exchange etc) will earn you around 250-750 exp.

Teleporting and Runecrafting
This method works best when running air runes but is also good for earth runes. When you have gotten to the altar and crafted your runes you can teleport back to the bank and save some time in your trip. This method increases your exp/hr while runecrafting and overall increases your earnings per hour rather than runecrafting without teleporting.

Magic times two
A method that is growing in popularity is high alchemy while telekinetic grabbing wines of Zamorak. The wines are located at a small church North-East of the goblin village. Bring your runes for telegrabbing, teleporting to Falador (if you don't have the Lumbridge explorers ring 2) and high alchemy and wield an air staff. Telegrabbing is required as if you simply grab the wine, the monks in the church will attack you. While you wait for the wine to respawn you can high alch 8 times before it comes back.

High Alching and smithing/cooking/runecrafting/crafting/walking around
High alchemy can be added to almost any skill. For instance, smelting at Al Kharid. While going to the furnace and going back to the bank from the furnace you can high alch. In fact, if anything requires walking you can high alch while you're walking. Please note, high alching can only be done without stopping if you aren't running.

Killing the Lesser Demon in the Wizard Tower and Firemaking
One way to train magic easily is by killing the Lesser Demon in the Wizard Tower, since you get over 300 experience per kill but simply need to attack, and can change windows while you wait for him to die. While waiting for him to respawn, there is a spawn of 3 normal logs nearby (on the same floor) which you can light. By setting a fire and adding the other two to the bonfire, this nets an extra 140 Firemaking experience and if you are quick, can be done during the respawn time. You can also telegrab some of the drops for more magic experience, and make a profit as well.

Mining and superheating
Mining and superheating is a popular way to train multiple skills at once. A good place to do this is the Lumbridge swamp advanced mine. This spot is often low in population as it's quite isolated. Crandor and the Al Kharid mine can also be good spots. A mining and smithing level of 55 and a Magic level of 43 are required for these spots. A mining and smithing level of 70 are also good for mining/smelting adamantite. Bring a rune pickaxe, about 25+ nature runes, a staff of fire and a coal bag (optional (costs 4,000 Dungeoneering tokens)). Simply mine an ore then mine enough coal to superheat it into a bar. Using this method making Adamant bars and a coal bag you can stay in your spot without having to bank for 25 minutes.

Prayer
Prayer can be trained alongside a combat skill while killing monsters and burying their bones. It can also be trained singularly by powerburying.

Ranged
Killing monsters that drop bones and burying their bones will give you ranged and prayer experience.

Runecrafting
Runecrafting can be trained alongside many other skills, although, due to its low exp/hr the methods are listed under other skills or in the case of mining and running to the altar without banking on the runecrafting page.

Smithing and Mining
Bring the best pickaxe you have and head over to the Al Kharid mining site. Go and start mining the ores of your choice. When your inventory is full you can head back towards the bank, stopping at the furnace on the way and smelting your ores before banking them.

Note: If you are under 49 combat there are highly aggressive Scorpions. If you are over 49 combat they will not attack you.

Woodcutting and Runecrafting
Although woodcutting gains the most exp/hr out of the 2 skills, runecrafting takes the most time. The best way to train using this method is running at the earth altar. Bring a rune hatchet, earth talisman (or, preferably an earth tiara) and the maximum amount of rune essence you can carry. Once you have visited the altar and crafted your runes you can cut down the yew tree just outside of the altar. The tree respawns once every 2 runs. This method is an efficient way to train as it combines 2 skilling trips in 1 and it has a higher exp/hr than runecrafting alone.

Making urns and alching
This can either be done at the Barbarian Village, Draynor Village, or in the the Crafting guild. First, you mine a full inventory of clay. Then go to the nearsest water soruce and turn it into soft clay. Use the soft clay on the potter's wheel, creating an urn. Then, fire the urn in the pottery furnace. Use High Level Alchemy on the urn (a fire staff helps). Depending on the urn and the price of nature runes you could make a profit doing this and get decent experience rate.