Free-to-play Smithing training

Always favour platebodies > platelegs > shortswords, then sell to speciality shops/Grand Exchange

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. For ironman characters to obtain the iron bars, head to the trees located in level 18 Wilderness next to the bears west of the Graveyard of Shadows

Levels 1-15
If questing isn't your thing and you'd prefer straight Smithing, Bronze bars provide 6.2 experience upon creation of a bar in the forge. Every bar of bronze used in the process of forging weapons or armor will grant you 12.5 experience. For example: A bronze platebody requires 5 bronze bars to forge. 5 x 12.5=62.5. Forging a bronze platebody, therefore, awards you with 62.5 experience in the Smithing skill. (Bronze platebodies aren't available until level 18)

Level 15-35
At level 15 you can smelt iron, though it is not advisable. Players only have a 50% success rate when smelting iron. Forging Iron items is generally skipped over as it is more economical, time and money-wise, to either smelt Bronze bars and forge Bronze items until steel bars can be smelted, or simply complete the Knight's Sword quest and skip to level 29. Players are able to achieve 100% success if they are using superheat magic, although it is not advisable because of the cost of nature runes.

Levels 29-40
Silver bars are favoured by most players as it is an easy way to get Crafting experience along the way.

Level 30-50
Steel or Iron. Specifically for regular ironman, this may be the best, since iron ore is so quick to collect, and you only need 2 coal per iron ore for steel for ultimate ironman, this method is very slow unless you have nature runes for superheat, but it is better to save nature runes for superheating mithril.

Levels 50-70
Superheating mithril Great exp, but not profitable.

Levels 70-85
Superheating adamantite Not much better.

Levels 85-99
Superheating runite bars is the best, good luck getting here!