Pay-to-play Smithing training

Smelting
Players can smelt ores into bars at a furnace for Smithing experience. Alternatively, players can superheat which allows players to smelt at a bank or at a mine for the cost of 1 nature rune and 4 fire runes. Players only have a 50% chance of smelting iron ore at a furnace unless they use a ring of forging or use the superheat spell.

Smithing
Players can choose to smith bars into armour and other metal items at an anvil. Usually the best things to smith are iron knives, dart tips and platebodies, depending on whether the player wants fast experience or profit.

Blast Furnace
Players can play the minigame Blast Furnace to smelt ores using half the required amount of coal. There are Clan Chats that provide free services for Blast Furnace, making it wildly popular as a method for training and a method of money making.

Quest experience rewards
Total: 49,482 Experience
 * 1,000 - Recipe for Disaster
 * 2,257 - Heroes Quest
 * 2,500 - The Giant Dwarf
 * 5,000 - Between a Rock...
 * 5,000 - Elemental Workshop I
 * 6,500 - Devious Minds
 * 7,000 - Cabin Fever
 * 7,500 - Elemental Workshop II
 * 12,725 - The Knight's Sword

Levels 1-29 – Questing
The Knight's Sword is a free-to-play quest that gives 12,725 Smithing experience upon completion. This reward would elevate a level 1 Smithing to level 29 immediately. It is strongly recommended that people interested in Smithing do this quest as soon as possible.

Levels 1-30 – Bronze items
If completing The Knight's Sword isn't an option, smith the highest-level bronze item you're able to.

Levels 30-60 – Iron items
Smith the highest-level iron item you're able to.

Levels 60-99 – Gold bars (Blast Furnace)
Smelting gold bars in the Blast Furnace is the fastest, although a costly way to train Smithing. This requires having access to goldsmith gauntlets (requires completion of Family Crest), which increase the base experience of 22.5 to 56.2 experience per bar. Players can expect up to 300,000 experience per hour with this method if using one of the official Blast Furnace worlds, which have dwarven workers operating the Blast Furnace.

231,268 gold ores are required to achieve 99 Smithing if using the goldsmith gauntlets. Gold ores are worth and gold bars are worth, which means that, when using Goldsmith gauntlets for 56.2 experience per bar, this can be done for  gp per experience or ~74,930,832gp before selling smithed bars, which would sell for ~16,420,028 leading to an overall loss of ~58,510,804

Level 18-99 - Bolts (10/bar)
Fletchers look for stackable materials that make stackable ammunition, allowing for cross-training. Bolts are in demand by fletchers who haven't completed The Tourist Trap. They can be given bolt tips and enchanted for enchanted bolts.

At level 18, iron bolts (unf) can be made from iron bars which can be finished into iron bolts with 39 fletching and a feather.

At level 33, steel bolts (unf) can be made from steel bars, which can be finished into steel bolts with 46 fletching and a feather.

At level 53, mithril bolts (unf) can be made from mithril bars, which can be finished into mithril bolts with 54 fletching and a feather.

At level 73, adamant bolts (unf) can be made from adamantite bars, which can be finished into adamant bolts with 61 fletching and a feather.

Level 19-34 – Iron nails
At level 19 members can make 15 iron nails from an iron bar. It is possible to make 900 iron bars into 13,500 iron nails per hour at a leisurely pace. This method provides ~25k experience/hr, which is more than double the experience from smelting iron bars.

Level 30-99 – Blast Furnace

At level 30 players can start smelting Steel Bar, the very first bar requiring coal. While normally smelting steel bar result in a loss, smelting steel bar at blast furnace actually makes a  profit due to its halved coal consumption. Smelting at blast furnace requires per hour from the coffer, and an additional  per 10 minutes to be manually paid for anyone below 60 smithing. One can make up to 4,000 steel bars per hour with the help of both Coal bag and Ice gloves, 3,000 bars with only Ice gloves and 2,500 bars with neither. Bars can be sold to grand exchange or made into dart tips or cannon balls for further experience and profit.

Levels 34-99 – Dart tips
Dart tips are often in high demand due to their use of powertraining Fletching, thus smithing them usually makes profit or breaks even. Always check the prices before attempting to do this. Making any type of dart tips requires completion of The Tourist Trap quest.

At level 34, you can start smithing steel dart tips, which yields coins per experience with the current prices. This method grants 37.5 experience per steel bar, resulting an experience rate of roughly 37,000 experience per hour. Doing this method from level 34 to 54 would require 3,905 steel bars.

At level 54, you can start smithing mithril dart tips, which yields coins per experience with the current prices. This method grants 50 experience per mithril bar, resulting an experience rate of roughly 50,000 experience per hour. Doing this method from level 54 to 99 would require 257,672 mithril bars.

At level 74, you can start making adamant dart tips, which yields coins per experience with the current prices. This method grants 62.5 experience per adamantite bar, resulting an experience rate of roughly 65,000 experience per hour. Sometimes making adamant dart tips will result in a small loss, so the player may wish to continue with mithril dart tips instead. Doing this method from level 74 to 99 would require 191,011 adamantite bars.

Levels 35-99 – Cannonballs
Smelting cannonballs from steel bars is profitable; however very slow experience. To smelt cannonballs, players must complete the Dwarf Cannon quest. Each steel bar, costing, gives 25.6 experience and 4 cannonballs, worth , resulting in a profit of coins per experience. 507,704 steel bars are required to achieve 99 Smithing. (~14k xp/hr at a rate of about 540 bars per hour).

Furnaces

 * Al-Kharid by the bank.
 * Edgeville no longer requires completion of the Easy Varrock Diary, however there is still a 10% chance of smelting two bars at once while wearing Varrock armour.
 * Falador Square.
 * Neitiznot north-east from the bank chest. This is the closest furnace to a bank. However, The Fremennik Isles has to have been started to use this furnace.
 * Port Phasmatys directly across from the bank. This is the second closest furnace to a bank, with Neitiznot being the better option.
 * Lumbridge near the general store.
 * Wilderness Resource Area.
 * East Ardougne next to the church, south of the north bank.
 * Shilo Village next to bank.

Anvils

 * Across from Varrock West Bank.
 * South from Yanille Bank.
 * North of Falador, east of Taverley, Doric's hut after Doric's Quest.
 * Northern hut of Tai Bwo Wannai.
 * Port Khazard has a bank near it now but is still inefficient for smithing.
 * Northern West Ardougne.
 * South-western Rellekka.
 * West of the Ranging Guild.
 * Nardah.
 * Wilderness Resource Area.
 * Void Knight Outpost.
 * Blast Furnace