Pay-to-play Smithing training

Quests 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
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 smith to level 29 immediately. It is strongly recommended that people interested in Smithing do this quest as soon as possible.

Levels 1-15
Bronze bars provide 6.2 xp or 12.5 xp.

Level 15-35
At level 15 you can smelt iron. However, players only have a 50% success rate when smelting iron. Players are able to achieve 100% success if they are wearing a ring of forging, using superheat magic or use the Blast Furnace located in Keldagrim. (~12.8k xp/hr at 100% success rate; ~6.4k xp/hr at 50% success rate)

Level 35-99
Smelting cannonballs from steel bars is extremely profitable however very slow experience. To smelt cannonballs, players must complete the Dwarf Cannon quest. Each steel bar gives 25.6 experience and 4 cannonballs. 507,704 steel bars are required to achieve 99 smithing. (~14k xp/hr)

Level 40-99
Smelting gold bars is one of the most cost efficient training methods for smithing. This requires Goldsmith gauntlets from the Family Crest quest. The gauntlets increase the base xp of 22.5 to 56.2 xp per bar. 231,268 gold ores are required to achieve 99 smithing if using the goldsmith gauntlets.(~50k xp/hr)

With the new varrock platebody and edgeville furnace, it is possible to gain upwards of 65k xp/hr.

Level 54-74
Making mithril dart tips is a very good way to train smithing. This requires partial completion of Tourist trap and 54 smithing. 1 mithril bar used (which is around 950-1k gp) gives 50 xp makes 10 dart tips which sell for 95 gp each instantly. This method is very afk, a good alternative to smelting gold ore and decent xp (~45k xp/hr). Doing this method from 54-99 would require 257,672 mithril bars.

Level 74-99
When you get to level 74 smithing you should start making adamant dart tips instead of mithril dart tips. 1 adamant bar will give you 62.5 xp. This is around 60k xp/hr.

Smelting
Players can smelt ores into bars at a furnace for Smithing XP. 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.

Some players turn steel bars into cannonballs at a furnace after they have completed the quest Dwarf Cannon.

Players who have completed Family Crest can use Goldsmith gauntlets to increase the XP for smithing gold ore from 25 XP to 56.2 XP. This is one of the fastest ways to gain Smithing XP.

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

Blast Furnace
Players can play the minigame Blast Furnace to smelt ores using half the required amount of coal.

It is advised to use the "Osrs Bf" cc to teleport to Blast Furnace and to get more bars/hour.

Other

 * Another great way to gain Smithing experience is at the Motherload Mine. One can world hop and repair the two broken struts in the center of the Motherload Mine. Repairing one strut awards the player with 60 experience (or 1.5 times of your Smithing leve l. In this case the test was done at level 40 Smithing); at a good world hopping rate (OSBuddy recommended) one can gain upwards of 45,000 smithing experience per hour.

Furnaces

 * Al-Kharid by the bank
 * Edgeville requires completion of at least Easy Varrock Diary. 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 Arena.
 * East Ardougne next to the church, south of the north bank.

Anvils

 * Across from Varrock West Bank.
 * South from Yanille Bank.
 * North of Falador, east of Taverly, Doric's house after Doric's Quest.
 * Northern hut of Tai Bwo Wannai.
 * Port Khazard.
 * Northern West Ardougne.
 * Southwestern Rellekka.
 * West of the Ranging Guild.
 * Nardah.
 * Wilderness Resource Arena.